Coworker Workplace Violence: Type 3 Warning Signs and Response

Type 3 workplace violence is violence or threats by a current or former employee against coworkers, supervisors or managers. It is hard to talk about, because the person of concern may still have a badge and a desk down the hall. Coworkers are often in a position to see warning behavior early.

This guide covers the research on coworker violence, the warning behaviors that matter, what to do if a coworker threatens you, and how an employer can respond with a fair, documented process. For the full program view, see our workplace violence prevention and response services. If anyone is in immediate danger, call 911.

Where this guidance comes from. This article draws on the Bureau of Labor Statistics (BLS), NIOSH, OSHA, the FBI, the Bureau of Justice Statistics (BJS) and Arizona statutes, plus our team’s field experience running security posts and investigations in Arizona. Every figure carries its data year.

What is Type 3 workplace violence?

The four-type model comes from the University of Iowa Injury Prevention Research Center’s 2001 report to the nation. It defines Type III as cases where “the perpetrator is an employee or past employee of the business who attacks or threatens another employee(s).” The FBI uses the same typology, describing Type 3 as “violence against coworkers, supervisors, or managers by a present or former employee.”

Two details matter. Former employees count, so a person fired months ago who returns to make threats is still Type 3. And the conduct does not have to be physical. OSHA’s definition includes “harassment, intimidation, or other threatening behavior,” and NIOSH describes a range from verbal abuse to physical assault.

Related: the four types of workplace violence. Type 1 is criminal intent by outsiders. Type 2 involves customers and patients (see our guide to customer and client violence at work). Type 4 is a personal relationship that follows an employee to work, covered in our guide to domestic violence that reaches the job.

The numbers: how common is coworker violence?

In 2017, BLS counted 77 workplace homicides committed “by co-workers or work associates,” out of 458 total. That made them “the second largest assailant group behind robbers (128),” or about 16.8% of workplace homicides that year.

Yearly BLS counts for co-worker or work associate homicides were 74 in 2013, 61 in 2014, 66 in 2015, 66 in 2016 and 77 in 2017, for 344 over five years. In 2016, co-workers were 14% of assailants in workplace homicides of women.

Why the data stops in 2017: this is the latest BLS breakdown by assailant available. BLS releases since about 2018 do not publish homicides by assailant type. BLS counted 470 workplace homicides in 2024 but does not say how many involved coworkers. A 2001 university report put worker-on-worker cases at about 7% of workplace homicides, based on 1990s data, so treat that as historical.

For nonfatal incidents, the BJS report Indicators of Workplace Violence, 2019 found that coworkers committed 7% and supervisors 3% of nonfatal workplace violence in 2015 to 2019. Only about 39% of all nonfatal incidents were reported to police, which is one reason internal reporting channels matter.

There is no profile, so watch behavior

The FBI is direct: “No ‘profile’ or litmus test exists to indicate whether an employee might become violent. Instead, it is important for employers and employees alike to remain alert to problematic behavior that, in combination, could point to possible violence.”

Profiles based on personality, age, background or a mental health condition produce false alarms, invite discrimination and miss people who do not fit the stereotype. Behavior can be observed, documented and addressed. In the FBI’s active shooter study, only 25% had a verified mental illness diagnosis. What a person says and does over time matters more.

The pathway to violence

The FBI guide Making Prevention a Reality explains that “persons intending to engage in targeted violent acts move along an identifiable pathway on their journey to attack.” The pathway begins with “the formation of a deeply held personal grievance or humiliation,” followed by research, planning and preparation. Threat assessment researchers Calhoun and Weston describe a six-step model:

1. Grievance: a sense of being wronged or humiliated.
2. Ideation: the person starts to see violence as justified.
3. Research and planning: learning about the target, schedules or location.
4. Preparation: getting weapons, equipment or access.
5. Breach: testing or getting past security.
6. Attack.

At work, the grievance might involve discipline, a lost promotion or a long conflict with a supervisor. Every step before the attack is a chance to intervene.

What the FBI’s pre-attack behaviors study found

The FBI’s A Study of the Pre-Attack Behaviors of Active Shooters in the United States Between 2000 and 2013 (June 2018) looked at 63 active shooters in all settings. It is not a study of workplace violence in general, but it shows how visible the warning period can be:

• “On average, each active shooter displayed 4 to 5 concerning behaviors over time.”
• 79% had an identifiable primary grievance.
• 56% leaked intent to commit violence.
• Co-workers noticed concerning behaviors for 40% of shooters (25 of 63).
• “In 41% of the cases the concerning behavior was reported to law enforcement.”
• 77% spent a week or longer planning.
• Only 25% had a verified mental illness diagnosis.
• Job-related problems were a stressor for 35%.

Warning signs: the FBI’s risk indicators

The FBI lists behaviors that, especially in combination, deserve attention:

• Increasing belligerence
• Ominous, specific threats
• Hypersensitivity to criticism
• Recent acquisition of, or fascination with, weapons
• Outbursts of anger

Add a fixed grievance the person keeps returning to and leaked intent, such as talk of “making them pay.” No single item proves anything. A cluster, or a change in behavior over weeks, is a reason to call in the threat assessment team.

What to do if a coworker threatens you

Take a threat seriously even if others brush it off. These steps keep you safer and create a usable record:

1. Get safe first. If the threat feels imminent, move away and call 911. Do not confront the person.
2. Write it down. Record the date, time, place, exact words and any witnesses the same day.
3. Preserve messages. Keep texts, emails, chats, voicemails and posts. Screenshot the sender and date. Do not delete them or reply in anger.
4. Report it. Use your employer’s channel: supervisor, HR, security or a hotline. If your supervisor made the threat, go to HR or the next level.
5. Ask about safety measures, such as a different shift, workspace or parking spot, or an escort to your car.
6. Consider a police report. In Arizona, threatening physical injury “by word or conduct” can be a crime under A.R.S. 13-1202.

What employers should do about coworker threats

A good response is fast, proportionate and documented. Our guide to a written prevention program under OSHA guidance covers the broader program. These pieces matter most for Type 3.

Make reporting easy and safe

The FBI recommends a designated office or person to receive reports, and possibly an anonymous hotline. Tell employees what to report and that retaliation will not be tolerated.

Build a behavioral threat assessment team

The FBI advises that a prevention program “should designate the personnel who will be specifically responsible for overseeing the organization’s antiviolence policy, including threat assessment and crisis management.” Making Prevention a Reality recommends multidisciplinary teams with core and ad hoc members.

The ASIS WVPI AA-2020 standard covers “policies, processes, and protocols” to “identify, assess, respond to, and mitigate threatening or intimidating behavior,” and ASIS stresses behavioral threat assessment teams. Core members often come from HR, security, legal and management, with outside specialists added when a case calls for them.

Triage the concern

A simple triage scale keeps the team consistent and helps avoid both under-reaction and over-reaction:

Concern level	Examples of behavior	Typical response
Low	Rude comments, one heated argument, venting with no threat or target	Supervisor conversation, documentation, coaching, watch for change
Moderate	Repeated anger outbursts, hypersensitivity to criticism, a fixed grievance against a named person, veiled remarks	Threat assessment team review, witness interviews, written expectations, support referral, follow-up plan
High	Ominous or specific threats, new fascination with weapons, leaked intent, interest in a target’s schedule	Paid leave pending review, access changes, security presence, formal investigation, legal counsel, consider police and an injunction
Imminent	A weapon shown or described, a stated time or place, the person on site in violation of a ban or order	Call 911, move people away, lockdown or evacuation per plan, then investigation and legal action

Use interim measures while you review

For moderate or high concerns, common interim measures include paid administrative leave pending review, so the step is not punishment before the facts are in. Others include suspending badge and remote access, separating schedules or work areas, and adding a uniformed security officer presence at entrances. Tell the threatened employee what is being done to protect them.

Investigate and document

Interview the reporter, witnesses and the employee of concern. Collect messages, video and access logs, and tie each finding to evidence. Our step-by-step internal investigation process explains how to keep the work neutral and court-ready.

Discipline “up to and including termination”

On zero tolerance, the FBI says “the intent is to set a standard of conduct, not a system of penalties.” Instead of “automatic termination,” policies should say violent behavior leads to penalties “up to and including termination.” That lets the response fit the facts.

Plan high-risk terminations

A termination can sharpen the grievance. Plan the timing, location, attendees, access cutoff, property return and security coverage, and treat the person with dignity. Our guide to threat assessment for terminated employees covers that plan and monitoring after separation.

Arizona legal tools for coworker threats

This section is general information, not legal advice. Talk to an Arizona attorney about your specific situation.

A.R.S. 12-1810, injunction against workplace harassment. “An employer or an authorized agent of an employer” may petition a magistrate, justice of the peace or superior court judge, including against a current or former employee. Harassment includes “a single threat or act of physical harm or damage,” so the employer does not have to wait for a pattern. The order can keep the person away from the employer’s property and bar contact with anyone on the property or doing official work duties.

Each petition names one defendant. The injunction lasts one year after service, and the defendant may request a hearing, held within ten days. When the employer knows who the target is, it must make a good faith effort to notify that person before filing. By comparison, an individual’s injunction under A.R.S. 12-1809 generally requires a series of acts.

A.R.S. 13-1202, threatening or intimidating. It is a crime to threaten or intimidate “by word or conduct” to “cause physical injury to another person or serious damage to the property of another.” It is generally a class 1 misdemeanor and a class 6 felony in certain cases, such as retaliation for reporting a crime.

Consider a hypothetical: a warehouse employee is let go for documented attendance problems. Two days later, he texts his former supervisor that he knows when her shift ends and she will “pay for this.” The employer could preserve the message, report it to police, notify the supervisor, add security at shift change and petition under A.R.S. 12-1810 based on that single threat.

Avoid over-reaction and discrimination

Over-reaction carries its own risk. Walking someone out in front of coworkers over a misunderstood joke can create the humiliation the pathway model warns about. Acting on a diagnosis, age, race, religion or other trait instead of conduct invites legal claims and misses real warning behavior. Keep the process fair:

• Base every decision on specific, documented behavior.
• Let the employee respond during the investigation.
• Apply the same triage levels to everyone, regardless of title.

How Honeybadger helps with coworker workplace violence

Honeybadger Solutions LLC is a veteran-owned, veteran-led security and investigations firm in Casa Grande, Arizona, serving the Phoenix metro, Pinal County and the Tucson area. We are an Arizona DPS-licensed private investigation agency (License No. 1759795) and a licensed security guard agency.

For Type 3 concerns, we provide behavioral threat assessment, neutral workplace investigations, armed and unarmed security officers for interim protection and high-risk terminations, background checks, surveillance and security assessments. We also build prevention programs and deliver supervisor and employee safety training.

If you are dealing with a threatening employee or former employee, submit a confidential service request online or book a consultation. For something that cannot wait for business hours, use the urgent intake form. If anyone is in immediate danger, call 911 first.

Why the online intake is faster than a phone call: it takes about two minutes, and your answers are routed straight to the specialist team that handles your kind of matter, whether that is cyber and forensics, investigations or field security. That team sees the full picture before it replies, so you skip phone tag and get a real answer and next steps sooner. If it cannot wait for business hours, use the urgent intake form, which is read seven days a week.

Frequently asked questions

What is Type 3 workplace violence?

Type 3 is violence or threats by a current or former employee against coworkers, supervisors or managers. The University of Iowa Injury Prevention Research Center and the FBI both use this definition. It includes threats and intimidation, not only physical attacks.

What should I do if a coworker threatens me?

Get safe and call 911 if the threat feels imminent. Write down what happened, save every message and report it to your supervisor, HR or security. Ask about interim safety measures, and consider a police report, since threatening or intimidating can be a crime under A.R.S. 13-1202.

Can my employer fire someone for a threat?

Often, yes. The FBI recommends policies that say violent behavior leads to penalties “up to and including termination” so the response fits the facts. Employers should investigate, document and plan any high-risk termination. Talk to an Arizona attorney about a specific case.

What is a behavioral threat assessment team?

It is a designated group, usually drawing on HR, security, legal and management, that receives reports of concerning behavior, assesses the risk and manages the response. The FBI recommends designating these personnel, and the ASIS WVPI AA-2020 standard emphasizes such teams.

Can an Arizona employer get an injunction against an employee?

Yes. Under A.R.S. 12-1810, an employer or its authorized agent can petition for an injunction against workplace harassment, including against a current or former employee. A single threat can qualify. The order lasts one year after service.

Are there warning signs before coworker violence?

Often. In an FBI study of 63 active shooters from 2000 to 2013, each showed 4 to 5 concerning behaviors on average and 56% leaked intent. FBI risk indicators include increasing belligerence, ominous threats, fascination with weapons and outbursts of anger. There is no profile, so focus on behavior.

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