Workplace violence refers to any aggressive or violent act toward a person who is performing his or her professional duties at the time of the act and regarded as a serious health and safety issue. At the end of the 20th century, incidents of violence on the workplace were reported increasingly in the United States and there were fatalities in many cases. One of the most shocking incidents happened in August 1986 in Edmond, Oklahoma, when post office employee Patrick H. Sherrill reported for work armed with three semi-automatic pistols. He killed 14 of his co-workers, wounded six and then committed suicide. Sherrill was described as "a disgruntled postal worker" who was fascinated by guns. He was reported to have been frustrated at being reprimanded by his supervisor, who died in the massacre. Between 1989 and 1997, official figures show that 15 homicide incidents related to workplace violence took place.
Workplace violence is recognized as a separate category of crime and includes a number of other offenses other than murder. Most frequently, employees and employers are engaged in less serious crimes such as assaults, domestic violence, stalking, threats, harassment (including sexual harassment) and physical or emotional abuse. It is not uncommon for such incidents to happen without being reported to the police or to company officials. The Federal Bureau of Justice (FBJ) estimated that in the period between 1993 and 1999 in the United States there were a total of 1,744,300 reported workplace violence incidents annually. The majority of cases were classified as assault, followed by simple assault and aggravated assault. A minority of incidents included robbery, rape and sexual assault.
Experts recognize four categories of workplace violence. The first one includes crimes committed by people who are not related to the workplace such as robberies. This category accounts for 80 percent of all workplace homicides. In the majority of cases the motive is theft or robbery and the offender is usually armed. Certain occupational groups, like bank tellers, retailers, gas station clerks or taxi drivers are more likely to be attacked. Preventative measures include CCTV surveillance, panic alarm devices and specialist employee training.
The second category is violence directed at employees by customers, clients, patients, students or any others for whom an organization provides services. This usually happens while employees are performing their daily responsibilities at work. The likelihood of being attacked at work is highest for police officers, security guards or mental health workers. Healthcare workers like doctors, nurses and aides are also frequently assaulted. In other jobs it is difficult to predict a possible violent incident but most commonly they are triggered by an argument between an employee and a customer or client over a delayed, denied or unsatisfactory service.
The third category is violence against co-workers, supervisors or managers. This category is the most difficult to deal with because if the previous two are likely to occur as an isolated event and not disturb the workplace environment afterwards, this type of violence may be continuous and may easily affect the whole structure and work process of the company. In most cases, violent acts of this type are caused by the cumulative effect of anger and frustration and frequently take time to escalate, which means that prevention is possible if problematic issues are dealt with on the spot and negative and destructive emotions are not bottled up. Studies show that in the majority of workplace violence in this category the offender has had previous confrontations with the assaulted person and the reasons for the outburst are often extensive criticism, underrating of a person's work, low self-esteem and ineffective coping strategies. Prevention can in fact start at the recruitment stage, by screening of potential employees to pick up on previous substance abuse, a history of frequent job changes and a tendency to avoid personal responsibility that could indicate the likelihood of workplace violence.
The last category of workplace violence is committed by a person such as a family member or partner. Employers are often at a loss to react because they feel like they are interfering in the employee's personal life. However, support is necessary because domestic violence victims are often embarrassed to share their problem. Prevention is possible and employers and colleagues should look for signs including frequent late arrivals or unexplained absenteeism, anxiety, depression, lack of concentration, isolation from co-workers or a sudden drop in work effectiveness and productivity.