It is the medical examiner’s responsibility to determine the identity of the deceased individual in a postmortem examination. The ideal result is a positive identification based on objective evidence without doubt as to the identity of the deceased. In some cases, a positive identification cannot be made. In these cases, a presumptive identification must be made in order to continue with the death investigation and the disposition of the remains.
A medical examiner’s most rewarding task is positively identifying unknown remains. When they successfully complete this task, police investigations can continue and the family has some peace of mind. However, when they are unable to make a positive identification it hinders the investigation. This can also lead to difficulties preparing and filing a death certificate as well as an inability to settle insurance claims. For these reasons, the medical examiner makes every possible attempt to positively identify the deceased individual.
Under most circumstances, the medical examiner has no difficulty identifying the individual. They are usually presented with an undecomposed body that has been identified previously by a family member. Even in these cases, the medical examiner obtains a color facial photo of the deceased with an identifying case number and two sets of classifiable fingerprints. They also record the height and weight of the deceased and retain a sample of the deceased’s blood for future DNA studies.
The most reliable method of identification is fingerprints. Ridge patterns on fingers can be classified in order to identify specific individuals. In the early 1900s, the New York City Civil Service Commission adopted the use of fingerprints for personal identification. The FBI followed suit soon after-it now has the largest collection of fingerprints in the world. However, an antemortem (before death) record of fingerprints must exist in order to establish the identity of the deceased using their fingerprints. If the victim was fingerprinted before starting a job or if they had been arrested, an antemortem record of their fingerprints would exist. An examiner would then compare this antemortem record to the set of fingerprints taken from the corpse. This latter set is referred to as a postmortem record.
Another method of identification is dental records. However, like fingerprints, some sort of antemortem record must exist in order to make a comparison. Antemortem radiography of the teeth is the most effective dental record-if these records exist, a positive identification can be made. Bone structures of the jaw, roots of the teeth, and sinuses are all unique to an individual, making information gathered from dental records very useful in forensic odontology. Forensic odontology is a forensic science, which handles, examines, and presents dental evidence in court. Dental evidence can be helpful in the identification of a person, but it can also help assess their age and whether or not there were signs of violence. For more information about forensic odontology, go here.
DNA can also be used as a technique for positive identification. Each person’s DNA is unique, except in the case of identical twins. Scientists first applied DNA to forensics in the 1980s. In order to establish identity using DNA, examiners should retain postmortem samples such as blood, hair with root bulb, skin, and bone marrow for comparison to antemortem samples. As mentioned before, postmortem samples are the samples collected by the medical examiner and the antemortem samples are samples which were taken at some time before death. These samples must contain mitochondrial DNA or nucleated cells to be of any value. Antemortem samples can be a variety of things: hair from a hairbrush used only by the individual, a lock of hair, or clothing with stains such as blood or sweat.
There are other forms of identification which are nonscientific. These methods don’t necessarily lead to a positive identification; they can only lead to a presumptive identification. This type of identification uses specific characteristics to come to a reasonable basis of identity for the unknown individual. Presumptive methods do not guarantee that your identification is 100% correct. They usually only give you enough evidence that you can presume your identification is correct.
This includes: sex, age, ancestry, eye color, and hair color are often used. Also, distinctive marks are very helpful. These marks can include tattoos, birthmarks, scars, or any piercings. A visual identification by a family member or friend is an easy way of identifying a deceased person as long as there isn’t extreme decomposition. Usually, the medical examiner takes photos of the body and has the living person attempt to identify the individual by looking at the photos. Circumstantial evidence useful in identifying the person is usually present either on the deceased or in the area where the body was found. Clothing, jewelry, glasses, or even paper found on the individual can provide clues to the individual’s identity. Also, depending on the circumstances, the location where the body was found can be a key piece of evidence. If the police found the body inside a home or a car registered to a specific person, it becomes easier to identify the deceased.
These various methods can all be used in postmortem identification. However, decomposition may make some of these methods very difficult. These methods are often used in combination with each other. For example, a distinctive mark like a tattoo could be used to narrow down the list of individuals whose antemortem samples you would have to gather. You would then only examine dental records or fingerprints from people who had the same tattoo. Most of these identification methods require antemortem samples, which may or may not exist. Luckily, in the case that there are no good antemortem samples, there’s a long list of other techniques that the examiner can employ.