Approximately two million violent crimes occur at work each year, and workplace violence costs employers more than $4 billion annually. Despite these numbers, many employers do not consider violence to be a realistic threat to their workplaces. Recent incidents, however, have focused national attention on this growing problem.

On January 26, 2006, ABC NEWS reported that a survey of American workers conducted by professor Aaron Schat of McMaster University in Canada revealed that over 40 percent of American workers reported being screamed at, insulted, threatened with physical violence or otherwise intimidated in the workplace. Six percent of employees reported that they experienced physical violence at work, such as slapping, kicking or being attacked with a weapon. Just four days after ABC's story, Jennifer San Marco, a 44-year-old former employee of the United States Postal Service (USPS) walked into a Goleta, CA, postal facility and shot and killed six workers before killing herself.

Ten days after the Goleta killings, the first in a USPS facility in eight years, the Los Angeles Daily News reported that violence at Los Angeles municipal workplaces jumped 20-fold in the past five years. Luckily, the City of Los Angeles is not representative of the entire nation. According to the Department of Labor, there has been a slight downward trend in the number of assaults and violent acts occurring in American workplaces over the past few years. Of the 898 assaults and violent acts that were reported in American workplaces between 1999 and 2003, 902 incidences occurred in 2003, while only 795 occurred in 2004. Although shootings remain the dominant form of workplace violence, the number of reported stabbings increased from 58 in 2003, to 66 in 2004.

Perpetrators of workplace violence often exhibit a pattern of behavioral characteristics that indicate their propensity for violence. Such characteristics may include: antisocial tendencies such as isolating themselves from others; a sense of moral superiority or righteousness; an inability to get along with others; a pattern of verbal harassment or abusive behavior toward others; an inability to accept responsibility for mistakes or a tendency to hold grudges or blame others for problems; a tendency to feel wronged or humiliated; a fascination with guns or weapons; a habit of resisting or challenging authority; and sudden, explosive displays of temper. According to reports, San Marco, the Goleta killer, had been forcibly placed on medical leave for psychological problems three years prior to her shooting spree. USPS inspector Randy DeGasperin told the Los Angeles Times that Marco's co-workers had been "concerned for her welfare" at the time of her leave.

Co-workers are not the only perpetrators of violence in American workplaces. According to Schat, 25 percent of workers reported that customers, clients, patients or other members of the general public subjected them to violent behavior in the workplace, and 13 percent of those surveyed indicated that members of management instigated some form of violent behavior (psychological or otherwise) towards their employees. In comparison, only 15 percent of workers reported co-workers as the source of violent episodes.

Employer Liability to the Victim

Employers may face significant legal liability for not taking adequate steps to prevent workplace violence. For example, victims often sue their employers (or the perpetrator's employer) for not adequately investigating the perpetrator's background before hiring the perpetrator. They also sue employers for not having fired the perpetrator after the employer had reason to suspect that the perpetrator might commit an act of violence. Likewise, victims commonly sue employers for not adequately supervising the perpetrator. These claims are commonly referred to as the torts of negligent hiring, negligent retention and negligent supervision, respectively.

In one Florida case, the jury awarded a million dollar judgment against a carpet cleaning company for negligently hiring an employee who strangled to death two customers. Had the employer investigated the employee's background, it would have learned that he had been discharged by a previous employer after being convicted of a violent crime. Similarly, a Colorado company was held liable for negligent supervision when an employee was assaulted by some co‑workers at a company sponsored Christmas party. The company had no reason to know that the perpetrators were prone to such violence.

In some cases, an employer's liability for violence can extend beyond the workplace. A woman's family won a $2.5 million judgment against the City of Los Angeles for negligent retention after her husband, a police officer, murdered her with his service revolver. Although the City knew that the police officer had threatened his wife with his service revolver, the City failed to discharge the officer or take his service revolver away. Thus, the City was found liable although the homicide occurred while the officer was off duty and away from his workplace.

An employer's liability for workplace violence can also spring from owning or leasing the property itself. In many states, landowners and persons in possession of property are legally obligated to protect people who enter the premises from situations that are known to be dangerous. In some circumstances, this means providing adequate security for the employer's premises. For instance, a jury awarded an employee $1.75 million because she was robbed in a parking lot controlled by her employer. Although the employer's security officers regularly patrolled that parking lot, the employer did not replace an officer who called in sick on the day that the employee was attacked.

Other causes of action for which an employer may be held liable to victims of workplace violence include sexual harassment, assault, battery, and intentional infliction of emotional distress. In addition, violent acts that occur at the workplace may result in investigations by law enforcement officers, which can cost employers in terms of decreased employee productivity.

Employer Liability to the Perpetrator

Employers may also face legal challenges from perpetrators of workplace violence. The Americans with Disabilities Act (ADA), prohibits discrimination in employment against qualified individuals with disabilities, including mental disabilities that may lead to violent episodes. The ADA requires that employers make reasonable accommodations that would permit such individuals to