• Active shooters have often experienced multiple major stressors in the previous year and believe their attack is fighting back against an injustice.
• Warning signs include combative behavior, increased substance use, depression, decreased hygiene, and obsession with weapons.

Active shooters typically have an “avenger mindset,” often believing they are fighting back against an injustice, either real or perceived, that has happened to them or someone they know. This feeling of having been wronged or treated unfairly can be triggered by stressors in their personal life (financial, legal, or relationship problems; drug or alcohol abuse; mental or physical ailments) or in the workplace (job loss, suspension, unequal or unfair treatment, harassment). Generally, active shooters experience multiple stressors (with an average of more than three) in the year before their attack.

Many active shooters exhibit warning signs or give hints of their intentions to others in person or through social media. The most important thing employees can do is report any indication of violence or retaliation — no matter how small it may seem — to their supervisor or Human Resources (HR) department.

While an employee who bullies, intimidates, or threatens coworkers should definitely be reported to the employer, other actions can also indicate that an individual may become violent. Warning signs may include:

• A notable increase in frustration or picking fights,
• An obsession with weapons,
• A decline in health or hygiene habits,
• An increase in alcohol or drug use, or
• Signs of suicidal thoughts or depression.

Employees should be encouraged to talk with their supervisor about how to report both actual violence and precursors to violence at their company.

The advice “If you see something, say something.” applies here. As in other situations where that advice is given, “saying something” may feel like an overreaction, but it is everyone’s responsibility to themselves and their coworkers to give supervisors the chance to address behavioral problems before they escalate.

Reporting worrisome conduct is not an attempt to get another individual in trouble, but a way to get that person help before anything bad happens. Many shootings could have been prevented had someone spoken out.

Employers have a legal requirement to take employees’ concerns seriously and, crucially, to protect them from any retaliation.