COMMON MEANS OF SUICIDE
Suicide by gunshot is by far the most popular form of suicide. A large majority of suicidal men use guns to kill themselves. Women, who historically have not used guns as frequently, are beginning to use guns more often now. An old cliche in police work is that women never shoot themselves in the head or face; however, this is simply not true.
Handguns are more popular as a suicidal weapon. However, in rural areas, long guns are more popular.
A substantial number of self-inflicted fatal gunshot wounds masquerade as "cleaning accidents". People who have studied these incidents do not believe that very many of them are actually accidents. They state that they are almost always suicidal. They point out that there is no part of the process of cleaning a gun which involves pressing the barrel of the gun close to the body or head. They further point out that there is no reason that the gun would be loaded midway through the cleaning process.
Forensic medical examiners usually consider the following to be proof that a gunshot wound was suicide: If the fatal wound was directed at the head, there should be a contact or near contact wound to the head. Evidence of these contact wounds will be described below. If the fatal shot was a shot to the torso with a long gun, there should be a downward left-to-right trajectory in right- handed people and a downward right-to-left trajectory with left-handed people. With handguns and long guns, with torso shot is almost always a contact wound, suicidal head wounds can be either contact or near-contact.
Medical examiners also believe that many hunting accidents are also suicides. As with cleaning accidents, there is simply no part of the activity of climbing out of a tree or over a fence or log with a gun that involves pressing the barrel of the gun close to one's body or head. Furthermore, the number of "accidental" shootings to the upper torso and head, is way out of line as compared with shootings to the other parts of the body..
As with all possible suicides, information for a psychological autopsy should be gathered and submitted to the medical examiner.
An essential element of an accidental or suicidal gunshot investigation is establishing the distance of the barrel from the body. This is a technical business which should be done by a laboratory expert. However, the on-scene investigator can make an estimate with which he can make an educated guess at the cause of death and a judgment of the consistency of all the evidence.
In order to conduct a proper evaluation of the distance estimate, the actual gun must be fired with the same ammunition used in the shooting. For that reason, the gun should certainly be gathered for evidence, along with any ammunition that might have been used to inflict the fatal wound.
Searing is a burning of the skin by the extremely hot gases which come out of the end of a gun barrel. If searing is present, it is evidence that the gun was either in contact or in near contact with the skin. That is, the end of the barrel was actually pressed against the skin. The soot which also came out of the end of the barrel will be seared into the edge of the wound and you will not be able to wash it away. If the soot can be washed away, it is evidence of a loose contact wound. That is, the end of the barrel was in contact with the body but not pressed tightly into it. If the seared area is somewhat larger than the very edge of the gunshot entry wound, this is evidence of a near contact wound. That is, the gun was within a fraction of an inch of the skin. The soot will then be seared in, and you will not be able to wash it away. If the area seared in soot is not circular, then the gun was held at an angle. There will be more of the soot seared in at the area of the skin nearer to the muzzle.
without searing indicate that the gun was held between 3/4" and 12" from the skin. The soot pattern may be circular, eccentric, oval, or pedal-shaped. Pedal-shaped shoot markings are sometimes caused by a flash suppressor arrangement on the end of a barrel.
In addition, there may be some soot from the cylinder of a revolver, a few inches from the entry wound, if the gun was held fairly close to the body at an angle. The shape of the soot pattern itself will tell you something about the angle at which the gun was held.
or tattooing, begin to occur as the gun is backed up to more than 1/2" from the body. The maximum distance from which powder burns can occur depends a good deal upon the type of gun used.
are orange brownish reddish in appearance. If they are gray or yellow, the victim was already dead when the shot was inflicted. Powder burns are caused by burning particles of powder which are ejected from the gun and become imbedded into the live skin. There is no actual burning of the skin which takes place. In that sense, the name powder burn is a misnomer. The particles simply penetrate into the skin and finish burning there by themselves. At closer than 1/2", the powder grains do not have a chance to spread out behind the bullet. They go into the entry wound rather than tattooing the skin around the entry wound.
is a phenomenon which tells you nothing about the distance from which the shot was fired. However, it is occasionally mistaken for some of the other items of evidence which can. Bullet wipe is a blackened ring around an entry wound. It is usually found on clothing rather than on the skin. (Incidentally, clothing is frequently moved aside prior to shooting oneself in a suicide. The lack of a bullet wound in the clothing is highly indicative of a suicide.) Bullet wipe is caused by the oils which are used in the manufacture of the bullet. These oils are wiped off by the clothing as the bullet penetrates leaving a blackened ring. Do not confuse this with searing or soot marking or the abrasion ring on skin.
is caused by the friction of a bullet piercing the skin. It leaves a narrow abraded ring around the entry hole. It tells you nothing whatsoever about the distance from which the bullet was fired and should not be confused with other markings. The abrasion ring may be hidden by soot markings and searing.
cannot be seen by the naked eye. They are microscopic metal shavings from the bullet itself, which sheared off the bullet as it flew down the barrel of the weapon. These fragments are shot from the barrel along with the bullet, and spread out under the influence of air resistance. Within a few feet, they may become embedded in the victim's clothing, or even skin. They show up nicely, on an x-ray. For this reason, the shooting victim should be x-rayed by the medical examiner before any clothing is removed, from several angles, to include closeups of each bullet wound. The pattern of bullet fragments may tell you somthing about the distance from which the fatal shot was fired
Trace evidence on hands....
In a suicidal shooting there may be evidence left on the hands which would help you to confirm that the victim was holding the weapon. Blood need not be present on the hands even with a contact wound. Blood may also not be present upon the weapon regardless of the distance from which the shot was fired.
Soot may be visible on the hands from either the cylinder of the revolver, the firing chamber of a rifle, or from the muzzle. This may help you to confirm that the hands were close to the weapon when the shot was fired. From the pattern upon the hands it may be possible to reconstruct the position of the hands relative to the gun. For instance, a pattern of soot around the facing edges of the forefinger and thumb might indicate that the hand was wrapped around the muzzle of the weapon, holding the muzzle to the body. Suicide victims do frequently position the muzzle carefully and hold it in position with both hands, one hand being on the muzzle.
Gun powder residue....
There are a number of different tests which have been developed over the years to attempt to confirm that gun power residue is present upon the hands. The first was a paraffin test which is no longer used. It detected nitrate and nitrites from the gun powder. However, nitrates and nitrites are common in the environment and do not tell you anything for sure as to whether or not there is gun powder residue on the hands. It is simply not specific enough to be a definitive test and may give you misleading results.
The Harrison Gilroy Test checked for the presence of barium, antimony, and lead on the hands. These substances are common in most of the primers used in cartridges. However, the Harrison Gilroy Test is not sensitive enough and may give misleading results. It is not considered useful by most experts.
The Neutron Activation Analysis test (NAA) detects barium and antimony but not lead. To collect samples for it, use cotton swabs with plastic handles. Dip the swabs in a mild hydrochloric or nitric acid solution and wipe the hands with the swabs in the area where residue is expected to be present. Unfortunately this test requires the use of nuclear reactor and is not available in Minnesota. It is relatively harmless to gather samples for it, however, and in extremely important cases, they might be gathered against the possibility that the samples could be submitted elsewhere.
The Flameless Atomic Absorption System (FAAS) detects antimony, lead, barium, and copper. It is capable of measuring the amounts of the various elements present. The sampling method is similar to that for the NAA system except that 5% nitric acid solution must be used. Four swabs should be taken from various parts of the hand. One sample of just the acid should be submitted also, for control.
Unfortunately the FAA method, does not differentiate between the various elements that it tests for. It only tests for the amount of all four elements that are present. Because barium is present in the soil, the results can be misleading. Furthermore the test has a 50% false negative rate and obviously is not extremely reliable.
The Scanning Electron Microscope method using x-ray analysis. It is considered the most reliable test but requires the use of a scanning electron microscope, a very expensive piece of equipment. Samples are taken from the hands with tape. The Scanning Electron Microscope looks for individual particles on the tape. It looks for the distinctive shape of gun powder residue and then x- rays the particles to determine the elements present within the particle. The false negative rate is only 10% for pistols but 50% for long guns. One of the nice things about the SEM method is that it is still possible to take a valid sample 12 hours after the shooting.
The Trace Metal Detection technique attempts to determine whether a hand has been in contact with a piece of metal. On some occasions it has been possible to show that the pattern of the gun itself shows in a pattern trace metal transfer to the skin of the hand. It is not, however, specific to metals used in guns. It will work for any metals and therefore the results are highly subjective. Furthermore the chemicals used to analyze the skin are believe to cause cancer. It is no longer a popular test and should certainly not be used on a live victim. The test itself if difficult to administer and should not be attempted by anyone not specially trained in its use.
Handguns are typically held to the temple, behind the ear, to the side or front of the forehead, in the mouth or under the chin, or to the heart. Long guns are usually fired pointing upwards, with the muzzle against the under-chin, in the mouth, or at the forehead, or pointing downwards and sideways into the lower chest area, or upwards and sideways into the upper chest area. If a longgun is used, the investigator must account for the ability of the victim to reach the trigger.
Either type of gun may or may not be held tightly against the skin, or at an angle to the skin. Each configuration produces characteristic evidence on the skin and characteristic entry and exit wounds.
Entry and Exit Wounds....
The entry wound may show soot marks, powder burns, abrasion ring, and possibly bullet wipe if the bullet penetrated clothing. It is typically approximately the size of the intruding projectile. Even a multiple pellet shotgun wound would be about the size of the end of the barrel if it was a close range shot.
The exit wound is typically much larger than the entry wound. An exception is when the part of the body the projectile exited from is pressed against a hard but penetrable surface such as a block of solid wood. In that case it may be fairly close to the size of the bullet itself. The exit wound is typically less regular in shape than the entry wound. It has no abrasion ring unless the skin was shored up by a object or firm clothing. However non-deformed ball ammunition may leave a small regular exit whether or not the skin was shored.
Suicidal shootings occasionally are marked by grazes where the victim apparently flinched or changed his mind before firing a preliminary shot. It is possible to determine the direction of a graze by looking for abrasion ring at the entry end of the graze and torn skin at the exit end.
The trajectory of a bullet shot from a distance will be straight but slightly parabolic as it travels through the air. With a close range shot, typical of suicides, the parabolic element of the trajectory if negligible. After entering the body, it may start to tumble and will usually not travel straight through the body. For this reason attempts to determine the exact angle of entry will never be precisely successful.
Post-mortem activity of the body....
Severe gun shot wounds might be thought to be instantaneously incapacitating. However, they are not. Gun shot victims have run hundred of yards and engaged in seemingly intelligent activity even with their hearts completed shattered and with major portions of their brains destroyed. In fact the human body can function normally for up to 10 seconds after the heart has completely ceased to function.
Even a major wound to the brain will not kill instantly. The basal ganglia of the brain, which is the lowest most central part of the brain, situated at the top of the neck and towards the back of the skull, controls bodily movement. Until the basal ganglia dies, coordinated movement of the body is possible, including running, use of the hands, and any other activity which does not necessitate intelligent decision making. The frontal lobes (the portion of the brain immediately behind the forehead) contain the intelligence functions. Although they are the most "human" part of the brain, they are the least critical to life. They do not control any of the life-sustaining organs and do not control motion. It is possible for the human body to live for years even after the frontal lobes have been removed.
Ejection of shells from the suicide weapon is not the type of motion controlled by the basal ganglia. It takes an intelligent decision to perform this motion. If the front portion of the brain has been destroyed by the suicidal shot, it is virtually impossible for the victim to purposely eject a shotgun shell or rifle cartridge. However, the mechanical action of the weapon in combination with the effect of recoil may eject a round. Examination of the weapon and effects of a recoil should be tested to see if that is a possibility.
A fairly common problem is the apparently suicide that has fired two shots into the head. Even in the case of instantaneous death and destruction of the basal ganglia, double head shots are possible in suicides. There is a phenomenon called "cadarvic spasm" which is an intense non-specific, uncontrolled contraction of the muscles of the limbs immediately after death. This is quite capable of causing a second pulling of the trigger after death.
Bullets typically leave a small, clean entry hole in the body, and do massive internal damage as they travel through or bounce around in, the body. If the bullet exits the body, the exit wound will be avulsed (tissue projecting outward above the skin's surface) and much larger than the size of the bullet. The path of the bullet through the body is not necessarily a straight line, nor is it in line with the flight of the bullet. Thus, the exit wound does not tell you exactly which direction the bullet came from.
The gun as evidence....
Do not be in a hurry to handle the gun at the scene. Even a loaded, cocked gun will not hurt anyone if it is left alone. Keep an eye on it, of course, and certainly do not left anyone near it until you are ready to collect it. (This is the rule for any and all evidence at the scene.)
Once it has been decided how the gun will be handled, then you should secure it in a safe container. There are three objectives in deciding on a method of handling the gun:
The number of live rounds remaining in the gun, the number of expended rounds in a revolver, and the location of each round removed from the gun by the police must be recorded. In order to determine this information, it will be necessary to handle the gun quite a bit. Therefore, field officers should not try to get this information. Simply secure the scene and leave the gun where it is if that can be done safely. Otherwise, collect it carefully, containerize it and secure it, but don't open it up. Leave that for later.
If a loaded gun has to be containerized for transportation, be sure to mark it as loaded, in large letters in a gaudy color, on all sides of the container. Handle the container as if it were a loaded gun (keep it pointed away from people).
Expended rounds should be searched for and collected. At the scene of an outdoors shooting, this may develop into quite a search, but it must be done. Fingerprints on the expended rounds can be very important evidence, so handle them carefully with tongs or other hard tools.
Hanging is the second or third most popular means of suicide, depending upon the area of the country. Hanging victims do tend to leave suicide notes, more so than other types of suicides. The most common knot used in a suicidal hanging is the slip knot, rather than the so called "hangman's knot". The knot is usually placed at the side of the neck but having the knot at the back of the head is also effective. Placing the knot at the front of the neck is less effective but can be fatal if the full weight of the body is hanging free.
The hands of the suicide victim are occasionally tied or handcuffed. This does not necessarily indicate homicide but certainly requires additional investigation. The important question is to determine whether or not the victim could have effected the hanging him/herself with his or hands restrained. Another definite possibility in the event the victim had restrained hands is that the death was a sex-related asphyxia accident.
The usual medical cause of death in a hanging is cerebral oximia; that is, lack of blood to the brain. The ligature around the neck, when pressure is applied to it, causes a closure of the blood vessels in the neck which are supposed to carry oxygenated blood to the brain. It is not closure of the air passages of the throat which causes death, but of the blood vessels.
In judicial hangings, the hung person is allowed to fall several feet, causing an instantaneous breakage of the neck. However, suicidal hangings rarely include this kind of force. It is not even necessary for the body to be fully suspended. Only 11 pounds of force is required to close off the carotid artery in the neck. A mere four pounds will close off the jugular vein, which brings used blood back to the heart. Sixty-six pounds is required to close off the vertebral artery, because it is protected by the neck bones. However, the vertebral artery can be closed off if the neck is extremely twisted, as it might be if the knot was on the side of the neck.
The airway may also be closed by the ligature. If the airway has been closed, it is usually by either crushing of the trachea or by displacement of the tongue. The tongue is displaced if the jaw is moved severely upward by the pressure of the ligature suspending the body. However, the airway does not need to be closed in order for hanging to produce death. Even if it has been closed in a hanging, it is not the cause of death. It would have caused death if the blood vessels had not been closed, but the closing of the blood vessels will cause death first.
Even with complete suspension of the body, the medical examiner will usually not find damage inside the neck.
As noted above, only four pounds of pressure is needed to close off the jugular vein and eleven pound to close off the carotid artery. Since the adult human head typically weighs between 10 and 12 pounds, it is by no means necessary for the complete weight of the body to be hung freely in order for a hanging to produce death. Simply leaning into a ligature or slumping down a little bit, or even just letting one's head hang loosely, will close off two of the important blood vessels that supply the brain. This is enough to produce unconsciousness in ten seconds and once unconscious, recovery is unlikely.
Inverted v-shaped furrow....
An inverted v-shaped furrow around the neck of a hanging victim is characteristic of suspension hanging deaths. This furrow should be parchment white immediately after death, with a congested looking reddish rim. With time it will turn brown and become more prominent if the body is not cut down immediately. The furrow should encircle the neck immediately under the ligature and then move upwards toward the point of the knot. Just before the two ends of the furrow close, they should taper out where the knot pulled away from the skin. Anytime the investigator does not see this inverted v-shaped furrow, he should question whether a hanging has actually occurred. If the furrow completely encircles the neck and is not v-shaped, then the death was not due to a suspension hanging. It may have been due to strangulation. Strangulation furrows tend fully encircle the neck, unless the strangler twisted the back of the ligature to tighten it. If the ligature was twisted, then only a few inches of the furrow, usually at the back of the neck, would not show.
It is extremely difficult to strangle oneself suicidally and homicide should be suspected. It is technically possible for someone to arrange a ligature strangulation of themselves; however, they have only 10-15 seconds to secure the ligature before they lose consciousness. If they have not properly secured it by that time, they will regain consciousness and survive.
Non-v-shaped furrows can be produced by non-suspensions hangings, where the victim just leaned against the ligature. In that case, the furrow would only go slightly more than half-way around the neck
Inverted v-shaped furrows can be artificially produced in a non-hanging death if the body is hung within two hours of death.
In the bodies of elderly patients and in newborns the investigator may see false furrows completely encircling the neck underneath folds of fatty skin. Decomposing bodies may also artificially produce furrows around the neck where the neck swells up against clothing.
Broad, soft or bulky ligatures, such as towels, may not leave ligature marks at all. Belts will leave a double furrow, as will a doubled rope loop. Sexual asphyxia accidental death victims may have no furrow, even if they did hang themselves with complete suspension (which they usually don't). They typically use some type of soft padding between the ligature and their neck to avoid leaving rope marks on their neck.
Scratches on neck....
It is not unusual for a hanging victim to have scratched at his neck, leaving skin under the fingernails and scrape marks in the area of the ligature around the neck. This does not indicate that the suicidal victim changed his mind or that it was homicide. The grabbing and prying at the ligatures is a completely instinctive move which may even have happened after loss of consciousness. It would be prudent to take scrapings from underneath the fingernails of the victim if scratch marks are seen on the neck; however, they would not produce meaningful evidence.
Usually the hanging victim will have a pale face and a protruding tongue. The tongue will have dried out by the time the investigator gets there. However, if the jugular vein had been closed off prior to the carotid artery being closed off, the victim will have a congested face--that is, puffy, full-looking, and red. If the victim has marked congestion in the face with petechiae (small flat red spots) and fine petechiae, then it is more likely that he was killed by strangulation. With strangulation, it is difficult to get complete closure of the arteries, so that some blood still flows to the victim's brain. However, it is easy to get complete closure of the jugular vein, so that the blood cannot escape from the brain and face. This causes the congestion.
Cutting the body down...
When the investigator is first called to the scene, he should first advise those at the scene to not cut the body down unless there is a chance of resuscitating the victim. There is no chance unless the victim was found within four minutes of hanging. Before cutting the body down, first take pictures. The medical examiner and coroner should be notified to see if they want to come. Diagrams and measurements of articles on the floor nearby should be taken. Look for drag marks on the floor, unexplained footprints, and things disturbed beyond the immediate vicinity of the body.
When you do cut the body down, avoid cutting the ligature along its length. The preferred place to cut the rope is on the backside of whatever it is suspended from. Do not cut through either knot and do not cut the noose off of the victim's neck. Transport the body to the morgue with the noose still in place.
As the body is cut down, do not let it collapse violently to the floor. Avoid causing any more injuries or marks upon the body if possible. Take note of any of the marks that you are inevitably going to leave on the body as you lower it to the floor and transport it. Such additional injuries serve to confuse the autopsy and simply require more investigation to explain, if you do not document them when you make them.
To determine if a hanging is homicidal in the absence of testimonial evidence, examine the body and the scene for marks of violence. Keep in mind that if there had been a big difference in strength between the victim and the murderer or if the victim had been incapacitated by drugs or alcohol or unconsciousness, there may be few marks of violence. For this reason, drug and alcohol testing should be requested with reference to any hanging victim. Also look for marks on the arms or chest of the victim where the victim might have been restrained or hoisted up to the ligature. Also check for drag marks on the floor or rug leading to the point of suspension.
The most common poisons used for suicide today are the various dangerous medicines which are available. There are, however, other poisons which can be used to commit suicide.
Most household poisons are acidic. The medical examiner will find reddened intestines and holes in the stomach, and possibly other burn-type injuries. It is helpful in these cases, to gather samples of the possible poisons from around the house.
The victim may show some reddening or browning of the mouth or lips. They may have vomited prior to death, or expelled blood from their mouth.
Most vegetable poisons act as a depressant on the central nervous system. Examples are barbiturates, opiates, belladonna medicines, strychnine, sleeping pills, and chloral hydrate. Death from an overdose of any of these vegetable poisons, is caused by the depression of the central nervous system, causing paralysis of the lung and heart muscles, leading to asphyxia. The victim will be cyanotic, like a heart attack victim. If the death is witnessed, the witnesses should have seen a progression of drowsiness, delirium, and coma. There may also have been convulsions.
Traditionally, the most common pills used for suicide have been tranquilizers and sleeping pills. There are a variety of brands and types which can be used. They all affect the central nervous system. An overdose causes the heart and/or lungs to quit, resulting in death by asphyxia.
Suicide by overdose of anti-depressant is becoming more popular now with the increased medical concern over suicide. Anti-depressants are medicines which attempt to re-regulate the affective system of people who suffer from unipolar or bipolar affective disorder. The most common of the anti-depressants are called tricyclic- anti-depressants. There are a number of different formulations and the various formulations are produced and marketed under a variety of different names. All of them are prescription drugs and many of them are highly toxic if taken in the wrong dosage. In fact, the Physician's Desk Reference, the standard reference manual for prescription drugs, lists suicide as a possible side effect of the tricyclic-anti-depressants.
Tricyclic-anti-depressants work directly upon the biochemicals which affect a person's mood. If the prescribing doctor has guessed wrong as to what is malfunctioning within the mood system, the tricyclic may have the opposite of the intended affect, driving the patient further into depression and increasing the chance of suicide.
Because the tricyclics work directly upon the biochemical processes within the central nervous system, they have a variety of affects, depending upon exactly how they work. If the death process was witnessed, the investigating officer should get detailed descriptions of the victim's physical and mental characteristics prior to death. This can then be compared by the medical examiner with the typical affects of overdose for whatever drug is suspected.
Anti-depressants are frequently prescribed in combination with powerful tranquilizers to help the depressed person feel better for the short term (most anti-depressants take several weeks to begin to affect the mood). They might also be prescribed in combination with other medications for physical problems since depressed people do tend to have a higher incidence of serious medical problems. If the victim has overdosed on a combination of pills, the affects may be bizarre but no less fatal. All of the pills should be gathered. An attempt should be made to find out how many pills they should have had left since last filling the prescription. The date the prescription was filled is printed on the front of the pill bottle.
Because psychiatrists are aware that the tricyclics can be dangerous and that depressed people are at risk for suicide, they frequently will only prescribe a minimal number of anti-depressant pills, so that the patient has to refill the prescription frequently. If the depressed patient has decided upon suicide, he or she may save the pills for a length of time in order to accumulate enough to affect suicide. Friends of the victim may recall that the victim has made excuses for not taking the pills or saying that he or she didn't need them anymore.
Patients who have Manic-Depression (Bipolar Affective Disorder), are usually prescribed lithium for the manic phase of their disorder. Lithium is also fatal if taken in overdose. Lithium is usually prescribed as lithium bicarbonate which comes under a variety of different trade names.
There are a variety of other medications upon which a suicidally bent patient might attempt to overdose. Unless these medications have a direct affect upon the respiratory or nervous system, they are unlikely to cause death. Their affects may be bizarre but not usually fatal.
Stimulants can also be taken for the purpose of affecting suicide, however, this is atypical. Usually it is tranquilizers that are used. Stimulants are never prescribed for depression and therefore the more powerful stimulants are usually not available to those bent upon suicide. If taken, an overdose of stimulants can typically cause death by heart attack. Prior to death, the victim will have been hyperactive and acting in bizarre manner.
It is possible to commit suicide by an overdose of illegal drugs. However, it is unusual for such a death to be ruled a suicide. Many states now label it as murder and label the drug seller as the murderer.
An illegal drug suicide may masquerade as an accident. The essential questions are; did the user know the strength and purity of the drug that he was using. Relying upon the strength and purity of a street drug is a lot like playing russian roulette; you never know which dose is going to kill you. The blood and urine of the deceased should certainly by analyzed for the strength of the drug. It is essential that the blood and urine be retrieved and preserved promptly to prevent any post mortem changes which would skew the results. When this has been determined, a judgment will have to be made as to whether the dose that the deceased took was sao far out of line as to suggest a suicidal intent.
On rare occasions it may be possible to get a sample of the drug that the deceased took. If this is possible, it should be analyzed for purity, and its purity compared with the drugs usually taken by the victim.
It takes an atmospheric concentration of 4 parts per thousand of carbon monoxide for an hour to kill a human being. The victim's skin typically turns cherry red or cherry pink (on a black or hispanic person, this will show up under the fingernails and on the lips). Although it is said to be a relatively painless way to die, it is not so pretty after loss of consciousness. The victim goes into convulsions, which may be violent enough to move the body several yards and/or contort it into positions that may seem hard to explain.
It is not unusual for suicidal carbon monoxide victims to lock or even nail the garage door shut, and put padding around supposed air leaks. The author has personally observed that several such victims have also unscrewed the light bulbs in the garage, for reasons that I cannot explain.
The investigation into an automotive carbon monoxide poisoning should always address the fact of whether or not the car was running at the time the death was discovered. If the first responder finds the car not running, the investigator must account for this prior to concluding his investigation.
Carbon monoxide is a colorless, tasteless, non-irritating gas. It's most frequent source as a suicide tool is automobile exhaust. Although it is possible for a carbon monoxide poisoning to be accidental, that is very rare. Automobile exhaust contains a number of other gases mixed with carbon monoxide which are extremely irritating and cause gagging and violent coughing. It is difficult to explain how a victim could succumb to carbon monoxide without first becoming aware that there was a problem.
Carbon monoxide binds with the hemeoproteins (especially hemoglobin) in the blood. It is stronger than oxygen in binding with the hemeoproteins, and once bound to them, does not let go. Over time, the concentration of carbon-monoxide in the blood will become many times higher than the concentration in the air. A concentration of 5 parts per thousand of carbon monoxide in the surrounding atmosphere, will cause a 75% displacement of oxygen in the blood in between 2 and 15 minutes. Because it displaces the oxygen, death is caused by asphyxiation - that is, lack of oxygen in the blood. In addition, carbon monoxide is directly toxic to the mitocondreal respiration response; that is, it interferes with your automatic breathing.
The organ most sensitive to damage from carbon monoxide is your brain. Within the brain, carbon monoxide does selective damage to various parts of the brain. If the victim of carbon monoxide poisoning is rescued, damage to his brain may progress over a period of 2 to 4 weeks. Certain cells, called pyramid cells, in the hypo-campus portion of the brain, may die several days later. The rescued victim may fully recover after a year or more.
Almost all people, but especially smokers, have a small amount of carbon monoxide in their blood all the time. Medically, 5% of the oxygen in the blood may be carbon monoxide is conciderred a safe maximum. Some heavy smokers have an average level of 13% of the oxygen in the blood being carbon monoxide. Between 20 and 30% carbon monoxide can be fatal to people who have other medical problems. In a healthy victim, a level of 50% will cause unconsciousness.
Symptoms of non-lethal elevated levels of carbon monoxide are headache, weakness, throbbing temples and fatigue.
An idling gasoline engine has between 2 and 10% carbon monoxide in its exhaust. If the exhaust if piped directed into an average size passenger compartment, carbon monoxide will occupy about 1.5% of the volume of the passenger compartment within about 5 minutes. This is enough to cause definite medical problems after 6 to 7 minutes from the time the car starts. At that level even if the car quits running or is turned off, the victim will die if he stays in the passenger compartment without ventilation.
Diesel engines produce very little carbon monoxide and are generally not considered to be able to produce death, if there is even minimal ventilation.
A suicide victim does not have to be in an enclosed space to commit suicide by automotive exhaust carbon monoxide. Simply lying near the exhaust pipe and breathing the exhausted gases can cause an 80% displacement of oxygen in the blood after some time.
In a pregnant woman, the concentration of carbon monoxide in the fetus lags behind that of the mother's. Even after the mother has died, it may be possible to save the fetus if it is advanced enough to be viable. Therefore, life support of the dead mother should be continued and the body rushed to the hospital.
The death process of carbon monoxide victims frequently includes strong convulsions. This is apparently caused by the onset by brain damage early in the death process. The convulsions can be strong enough to move the body across a floor or to move it around within an enclosed passenger compartment. In examining the death scene, these convulsions should be kept in mind. For instance, two lovers in a car found locked in an embrace would not appear to be a carbon monoxide death, unless they have used artificial means to restrain themselves in the embrace.
Two lovers found in a car on lover's lane apparently dead from carbon monoxide poisoning is not consistent with accidental death. The noxious fumes which accompany carbon monoxide in automotive exhaust would have driven the couple from the car long before they had died. Other causes of death should be investigated, and the possibility of suicide should be an element of the investigation. The same problem pretains to the apparently accidental death of a man "working on the car" in a closed garage.
The most obvious sign of carbon monoxide poisoning is the cherry red appearance of the lips and fingernails. On blacks, this cherry red color still shows up on the fingernails and inside the lips. Livor mortis in whites and other fair skinned races is also cherry red. The rest of the skin will have a robust, healthy appearance, rather than the usual pallor of death. In addition, if it has been some time since death there may be premature skin slippage; that is, the skin will be loose on the body. This is due to the elevated temperature caused by the car's exhaust into the passenger compartment.
Intentional suicides by smothering usually involve a plastic bag placed over the head. However this is also a popular means of sexual stimulus (see the section on Sexual Asphyxia). To eliminate homicide, check the hands for evidence of restraint. Look inside the lips for tooth mark impression where someone might have pressed the plastic against the victim's mouth. Even a moderately small amount of force will leave tooth marks inside the lips which will not self-recover after death.
With a plastic bag over one's head, it is impossible for the lungs to pass oxygen. Under these conditions, it takes about 90 seconds to pass out and about 4 minutes to die. The bag need not be tied at the bottom. Even a loose bag will effectively seal off the mouth and nose. There is no forensic means of detecting any trace evidence from this bag if it has been removed from the head prior to the body being discovered.
Do not overlook the possibility that the death could have been accidental. Plastic bags are also used by paint sniffers and as a means of sex-heightening asphyxia.
If a plastic bag has been used as a means of homicide, either the victim's hands will have been restrained, probably leaving marks, or the victim will have been in other ways incapacitated or possibly asleep.
SELF-INFLICTED KNIFE WOUNDS
Knife wounds in general....
When knives are used in a fight prior to the death of the victim, there would typically be defense wounds. Defense wounds tend to be on the hands and forearms, and to be quite severe-looking. They may look much worse than the fatal wounds. They can be distinguished from suicidal hesitation marks by their severity, and to a lesser extent, by their location and orientation along the body lines.
Langer Lines (or "longers") are the natural grain of the skin. When the skin is cut, as by a knife wound, the skin pulls back the along the langer lines. If the wound is lined up with the longers, the wound will appear to be longer than the width of the blade, even if it was stabbing wound. If the wound is perpendicular to the longers the wound may actually be shorter than the width of the blade, and would be more avulsed.
It is not possible to precisely determine the angle of a deep stab wound into the body. Any determination of the angle should be stated as only an approximation. The fact is that the internal organs of the trunk of the body and the muscles of the limbs normally move quite a bit. Even normal postures can move the internal organs substantially; therefore, any apparent angle with which a knife penetrates into the internal organs or muscles is only relevant if the body is placed in the same position it was in when the stab wound occurred. It is possible to state that a knife entered at an approximate angle.
Self-inflicted knife wounds....
Most non-fatal self-inflicted knife wounds are attempts to gain attention for the victim, and are not fatal or even serious. Officers who have dealt with such incidents typically find relatively neat, shallow, parallel wounds. In general, suicidal wounds are similar, only more severe. However, psychotic people have occasionally cut themselves with severely painful multiple wounds.
Suicidal knife wounds usually have hesitation marks very close by on the skin. These are caused by the knife being held poised on the skin in preparation for the actual cut or stab. They may be so close to the actual wound that they are partially obscured by the wound or the swelling around it. They are usually very superficial, and therefore not consistent with a wound inflicted by another person in a homicidal attack, unless there was a struggle with the knife poised over the victim.
If a homicidal knife wound is inflicted with a sweeping slash motion, then there should not be anything that looks like hesitation marks. However, if the killer had to position the knife with any care at all, such as preparatory to slashing someone's neck from behind, then it would be normal to see what would look like hesitation marks at the point of the beginning of the slash.
Except for wrist slashing, successful suicide by self-inflicted knife wounds is rare. As with homicide, it tends to be associated with passionate incidents. You would expect a person who commits suicide with a knife to have been a person with deep personality disturbances, more than the mere disorders that I have described above
Suicidal attempts that include wrist slashing frequently also include some other method such as pills or hanging. Wrist slashing by itself is not a very effective means of committing suicide and few people actually die of it. This is especially true if the victim cuts laterally across the wrist. He or she may do substantial damage to the important tendons which control the fingers. He or she may even cut an important artery or vein but the blood vessels will immediately draw back into the muscles surrounding them, effectively sealing off any major leakage of blood.
It is possible for a person to cut longitudinally along the wrist, laying open several important blood vessels along their length. This has been an effective means of causing enough blood loss to cause death. Even so it is not a sure method of killing oneself. If combined with other methods, such as drug overdose, loss of blood can contribute to death.
Since the cutting of a wrist is a somewhat painful event, it is normal to see some hesitation marks under or parallel to the final deep cut.
Knife wounds on the arms should be analyzed to determine if they are consistent with a suicide attempt or some other means of infliction. It is not at all unusual in a homicidal stabbing or attempted stabbing for the victim to have defensive cuts on his hands or arms. Defensive cuts tend to be deep and severe. They normally appear on the inside surfaces of the hands and the outside surfaces of the arms. These are generally considered to be non-suicidal cuts.
Jumping suicides seem to be more prone to leaving notes than other suicides. They may not, however, leave them in obvious places. Check the car, purse, apartment, workplace, and school lockers, as appropriate.
Check the body carefully for defense wounds. This will be complicated by the trauma injuries from the fall itself, but must be attempted if foul play cannot be ruled out by witnesses. Also check the body and clothing for marks and trace evidence that might have been picked up along the path of the fall. This might tell you something about the trajectory, and hence the horizontal speed at which the victim left the point of falling.
Check both the impact and departure points carefully for evidence.
A subdural hematoma is bleeding inside the skull, caused by a blunt force head injury. If you have an unexplained fatal subdural hematoma, you should always consider the possibility of death by falling. 72% of all fatal subdural hematomas are caused by falls. (25% are traffic injuries, only 3% are caused by other means, such as blows.) One key that a subdural hematoma is present, is that the victims eyes will roll away from the point of impact/injury, due to the mechanical pressure of the build-up of blood under the skull. Note that, in falls, the subdural hematoma occurs opposite the injury, not under the point of injury, on the skull. If the injury was caused by a blow from a club, the hematoma will be under the injury, and the eyes will roll towards the point of injury.
A drowning suicide may look very much like a accident. Drowning homicides are fairly apparent. What distinguishes a drowning suicide, in addition to the usual psychological autopsy factors, is that victim did not struggle. Witnesses, if there are any, may be able to say that the victim intentionally threw him or herself into the water and then made no attempt to get out of the water. For some reason, drowning victims rarely leave suicide notes.
It has been my personal observation that suicide by drowning is a method preferred by females.
Death by drowning is actually caused by hypoxemia, which is a condition of low oxygen in the blood. After the victim enters the water, he begins to hold his breath. This causes a blood condition of high carbon dioxide and low oxygen levels which forces the body to begin involuntary inhaling. Once the victim is under water, he inhales a large volume of water. The volume of water in the lungs becomes so great that water actually enters the blood through the lungs; however, this does no harm. Within a few minutes, the victim becomes unconscious due to lack of oxygenation of the blood and oxygen starvation of the brain. Inhaling continues for several more minutes prior to death.
The water that enters the lungs causes actual physical and chemical damage on the internal surfaces of the lungs. This damage process continues for a day, even if the victim is rescued prior to death. It causes a 75% loss of effective surface area in the lungs. For this reason, any rescued drowning victim should be immediately taken to a hospital for medical care.
In about 11% of cases the victim will display a syndrome known as "dry drowning" in which there is no water found in the lungs. In these cases a spasm of the larynx has completed shut off the airway as the body went under water. Despite the body's attempts at involuntary inhaling, no air can pass through the throat and the victim dies by normal asphyxia.
There are a number of post mortem changes which can identify drowning as the cause of death to a medical examiner. These include the formation of edema in the mouth, nose, and airway; water in the lungs; water in the stomach; dilation of the right ventricle of the heart; and a swollen brain, and in most cases, water damage to the surface of the lungs.
Puckering of the skin and/or goose flesh does occur post mortem in a drowning victim. However these phenomena are not specific to drowning and can be also be caused by other means of death.
The drowning victim's body typically sinks shortly after death. It will resurface 3 days to 3 weeks after death. The surfacing is caused by bloating, which increases the volume of the body without increasing the weight. Sometimes, because of air trapped in the clothing on the victim, the body will not sink at all. In really cold water, the putrefaction process is very slow, and the body may not bloat up, so it will not resurface for a very long time. Lake Superior is said to be too cold offshore for a drowning victim to decompose, so that they never surface.
The important questions in a drowning case are confirmation that the drowning was accidental and that the victim did in fact die of drowning. If the victim was dead prior to going into the water, then the characteristic indications of drowning will not be present. The testimony of witnesses should, as always, be taken critically and with an objective mind.
The existence of wounds on the body is not necessarily inconsistent with an accidental drowning. Bodies do get banged around in the water quite a bit, especially if they wash ashore. The injuries can be examined to determine of they occurred before or after death. Wounds received after death appear bloodless. The medical examiner can make a more scientific determination.
The body of the drowning victim will be pale rather than cyanotic, unless the water was quite warm. Since the body floats under the water after death with the head and limbs hanging down, you should see lividity in the face and extremities. The medical examiner should find lake water in the stomach.
The ME should also find a finely-textured sticky foam (edema) in the airway, which will ooze out the mouth and nostrils after several hours. This foam, which is the consistency of beaten egg whites and may be tinged with blood, is composed of proteins in the lung mixed with environmental water by convulsive breathing attempts just prior to death. It is characteristic of drowning deaths, although it can also accompany death by overdose of certain drugs.
Do not overlook the possibility of revival of a drowning victim, if they have not been under the water too long and the water was sufficiently cold.
PEDESTRIAN TRAFFIC SUICIDES
Causing oneself to be struck by a car is not an uncommon means of suicide. Typical scenario is that the suicide victim will lay down in the middle of the road in a dark spot while intoxicated, usually in the middle of the night. In this case, there would not be front end body damage to the car, and the victim will have wheel marks, and he or she may also have been struck by the undercarriage of the car transferring evidence onto it. Should the unfortunate driver choose the leave the scene of the "accident", you will have considerable difficulty in locating him if he does not eventually turn himself in, because there will be no obvious damage to the car.
Another typical scenario for pedestrian traffic suicides is that the victim will jump suddenly into the path of a vehicle with some dramatic gesture. In Duluth such gestures have included mooning the car or presenting oneself spread-eagle in front of the car.
This is also a favorite suicide method of very young children. They will dash or throw themselves in front of a car. It is almost impossible to prove that this was not an accident because, of course, children do accidentally and carelessly do such things. Careful interview of the witnesses in the investigation of such accidents may reveal that the child was waiting next to the road rather than engaged in a running game with other children, chasing a ball or other such likely scenario. If witnesses have noted that kind of behavior, then the child's lifestyle should be reviewed to see if it was consistent with a suicide attempt. Please refer to the section on Child Suicides at the beginning of this book.
The proper determination of cause of death in the case of a pedestrian traffic suicide is important not only for the usual reasons, but also for the peace of mind of the driver of the vehicle.
INTENTIONAL TRAFFIC CRASHES
The intentional traffic accident is probably the most common means of suicide that is typically misclassified. Unless the person has left a suicide note, it is not obvious from the physical evidence that is was anything other than an accident. This is especially true, since it is not uncommon for such drivers to be drunk at the time of these "accidents". The typical scenario for this kind of suicide is that it looks like the driver "fell asleep at the wheel". What makes it different is that the investigator will find no skid marks. He may also find that the car has run off the road at a sharper angle than someone who has simply lost control of a moving car. This sharper angle is a result of a decisive turn of the wheel rather than just meandering off the road. Another common aspect is that the car will have gone head on into a very solid object at an unnaturally high speed.
One means of positively demonstrating that it was an intentional act, is to examine the soles of the shoes the victim was wearing and compare it with any impressions left on the brake and throttle pedals. If the victim was intentionally driving into the solid object, he may have continued accelerating right up to the point of impact rather than trying to slow the car by putting his foot on the brake. If the shoe has any distinctive pattern whatsoever, it may be transferred onto the brake pedal by the sudden impact. If the shoe has a flat, unpatterned sole then the pattern of the brake pedal or throttle pedal may be impressed into the sole of the shoe. It takes some sophisticated lighting techniques to determine these patterns sometimes, but is very solid evidence of the intent of the driver.
Head-on car/grain truck accidents should also be analyzed as possible suicides, when it appears that the lone driver of the car was in the wrong lane and should have seen the truck coming. The presumed insurance settlement forthcoming to the car driver's family, and the spectacular nature of the death, may motivate some suicides to this method.
BIZARRE MEANS OF SUICIDE
There is almost no means of death which is too bizarre to have been suicide. There are cases in which people have cut off entire limbs and slashed their necks from side to side which have been confirmed as suicide. Intentionally burning oneself to death has become a means of political statement in other countries. Cases have also been recorded in America.
Several years ago in Duluth a young man killed himself by intentionally causing severe damage to his penis. He bled to death. This was determined to have been an accident, but it was not possible to eliminate suicidal intent. He had made suicide attempts previously.
Common sense would indicate that a person would not choose such severely painful methods of suicide. In general this is true. When such painful and bizarre methods of killing oneself are chosen, the investigator will be able to determine that the victim was both prone to suicide and the victim of either delusions or a severe personality disorder. Such victims may also have organic disorders exacerbating or contributing to their personality disorder, leading them to the bizarre and painful suicide.
Sex-related mishaps that result in violent death or difficult to investigate, mostly because people are reluctant to discuss and/or acknowledge private, unusual sexual practices. Sex accidents almost always look like suicide or murder. Family members of a sex accident victim would usually prefer to believe that their loved one was murderred or committed suicide, rather than accept that it was a "perversion" that caused the death.
Sex-related asphyxia accidents....
Sex-related asphyxia is a bizarre form of sexual pleasure. Persons who are susceptible to these accidents purposely cut off the supply of blood to their brain while masturbating. The reduced oxygenation of the brain reportedly gives them a heightened sexual experience. Occassionally, they die during such acts. But they do not intend to kill themselves.
The most common method of producing sexual asphyxia, is to strangle yourself during a sex act. The most common means of self-strangling is to "hang" yourself, with a litature cutting off or reducing the blood supply to the brain momentarily. You have to be careful not to use too much pressure, or to maintain the pressure for too long, or you will lose consciousness. Once unconscious, the mere weight of your head is frequently enough to cause closure of the juglar vein and carotid artery, which will kill you in 4 mintues.
Some persons get the same effect by putting plastic bags over their heads or sniffing solvents. This does not reduce the blood supply to the brain, but does reduce the amount of oxygen in the blood. If they are careless, they can lose consciousness before rescuing themselves, and asphyxiate while unconscious.
Typically, the sexual asphyxia accident victim will have been masturbating just prior to his or her death. You will find erotic literature and pictures within the victim's view, and possibly a mirror positioned for self-viewing. Cross-dressing is also common in such cases. When hanging or some other ligature strangulation method was involved in the accident, you will frequently find some padding between the neck and ligature. The padding is intended to prevent ligature marks on the neck. Padding on the neck is strong evidence that the hanging was accidental.
Sometimes the sexual aspect of these behaviors is accompanied by the acting out of suicide, bondage, or torture fantasies. The idea of suicide, sadomasochism, and bondage is sexually exciting to some people. They may handcuff themselves, hang themselves, cut themselves, and even leave suicide notes.
Bondage fantasies, when acted out in isolation, can leave the victim helpless if the self-release mechanism does not work. This may occasionally result in an exposure or starvation death, which would look at first like a homicide. What makes it accidental, is that they did not really intend to kill themselves. You will find some self-release mechanism or self-rescue arrangement. Of course, if the victim died, the mechanism did not work. The investigator must determine why, if the "accidental" determination is to stick.
If you find a suicide note, but suspect that the death was really an accident, analyze the content of the note. A person who does not really want to commit suicide is not likely to produce a note that looks genuine. Refer to the section on genuine suicide notes. Also check for evidence that the note was written well prior to the death. Some sex-fantasy accident victims use the same note over and over, like a sexy picture.
One might well suggest that such irresponsibly dangerous behavior is to suicide, what manslaughter is to homicide. Unfortunately, the law does not account for that, so it is a merely philosophical point. Sex-related asphyxia deaths are accidents, unless another person besides the victim is actively involved. When any person is involved in dangerous behavior which results in the death of another person, it is a manslaughter case.
A psychiatric autopsy may be useful in the investigation of a possible sex-related fatal accident. You would presumably not find thaat the victim fit the mold of a potential suicide. Furthermore, if the victim was depressed (had UAD) then there should have been litle interest in sex, and something is inconsistent. However, no policeman should attempt to make a final determination that the deceased had an organic mood disorder; that is a job for a professional in the psychiatric field.