10 Warning Signs of Workplace Violence Every Employee Should Know

Key Takeaways – Workplace violence rarely happens without warning — most incidents are preceded by observable behavioral red flags. – Understanding the warning signs of workplace violence empowers employees to intervene early and report concerns. – California law (SB 553) now requires employers to maintain workplace violence prevention plans, including employee training. – Reporting suspicious behavior is not overreacting — it’s a critical part of keeping everyone safe. – Professional training from a BSIS-certified academy like E3 Security Training Academy can prepare security teams and staff to recognize and respond to threats.

Why Recognizing Warning Signs of Workplace Violence Matters

Workplace violence is one of the leading causes of fatal occupational injuries in the United States. According to the Bureau of Labor Statistics, hundreds of workers are killed and thousands more are injured in workplace violence incidents every year.

But here’s what many people don’t realize: the vast majority of these incidents don’t happen out of nowhere. There are almost always warning signs of workplace violence — behavioral changes, verbal threats, and escalation patterns that, when recognized early, can prevent tragedy.

California has taken a proactive stance on this issue. With the passage of SB 553, most employers in the state are now required to implement workplace violence prevention plans and train their employees to recognize potential threats.

Whether you’re a security officer, a manager, or a front-line employee, knowing these warning signs could save lives — including your own.

The 10 Warning Signs You Need to Know

1. Verbal Threats or Intimidation

This is the most direct and obvious warning sign. Any statement that expresses intent to harm — whether directed at a specific person, a group, or the organization — must be taken seriously.

Threats can be direct (“I’m going to hurt you”) or veiled (“People around here better watch their backs”). Both warrant immediate reporting.

2. Fascination with Weapons or Violence

An employee who frequently talks about weapons, shows an unusual interest in mass violence events, or brings weapons-related content into the workplace may be signaling dangerous thinking patterns.

This doesn’t mean everyone who owns firearms is a risk. Context matters. It’s the obsessive or inappropriate nature of the interest that raises concern.

3. Sudden Changes in Behavior or Mood

One of the most commonly overlooked warning signs of workplace violence is a dramatic shift in someone’s personality or behavior. An employee who was once outgoing and suddenly becomes withdrawn — or someone who was calm and becomes agitated and hostile — may be struggling.

Watch for:

• Increased irritability or anger
• Social withdrawal or isolation
• Sudden drop in work performance
• Neglect of personal hygiene or appearance

4. Paranoid or Persecutory Beliefs

Employees who consistently believe they are being unfairly targeted, conspired against, or victimized by coworkers or management may be escalating toward violence. Statements like “Everyone is out to get me” or “They’re trying to ruin my life” should not be dismissed.

This is especially concerning when combined with other warning signs on this list.

5. History of Violent Behavior

Past behavior is one of the strongest predictors of future behavior. If an employee has a known history of violence — whether at previous workplaces, in personal relationships, or in legal records — this is a significant risk factor.

Managers and HR professionals should take this into account when assessing overall risk.

6. Excessive Grievances and Blame

While it’s normal to have occasional workplace complaints, an employee who constantly files grievances, blames others for every problem, and refuses to take accountability may be building a narrative that justifies future aggression.

The key indicator is escalation — complaints that grow more intense, more personal, and more frequent over time.

7. Substance Abuse Issues

Drug and alcohol abuse significantly increases the risk of violent behavior. Employees who show signs of substance abuse — coming to work impaired, declining performance, erratic behavior — may pose an elevated risk.

This is a sensitive topic that requires careful handling, but it should be part of any comprehensive threat assessment.

8. Stalking or Harassment Behaviors

Unwanted following, persistent unwelcome contact, monitoring someone’s schedule or movements, and sending disturbing messages are all forms of stalking behavior. These actions often escalate and can cross the line into physical violence.

Workplace stalking affects not only the targeted individual but creates fear throughout the entire team.

9. Expressions of Hopelessness or Suicidal Ideation

An employee who expresses feelings that “nothing matters anymore,” talks about having “no reason to live,” or makes comments about “ending it all” may be in crisis. Individuals who feel they have nothing to lose can become dangerous to themselves and others.

These statements always require immediate intervention — both as a matter of employee wellbeing and workplace safety.

10. Resistance to Authority and Policy Violations

Chronic defiance of rules, open hostility toward supervisors, and deliberate violations of workplace policy can signal an individual who is disengaging from social norms. When this behavior escalates — especially when combined with threats — it becomes a serious warning sign.

Pay attention to employees who seem to be “testing limits” with increasing boldness.

Understanding the Escalation Pattern

Warning signs of workplace violence typically don’t appear in isolation. They follow an escalation pattern that security professionals and HR teams should understand:

1. Early indicators — Behavioral changes, increased complaints, subtle verbal aggression
2. Escalation — Direct threats, confrontations, policy violations, intimidation
3. Crisis point — Actions that suggest imminent danger, such as bringing weapons to work, making specific plans, or issuing ultimatums

The goal of early recognition is to intervene at Stage 1 or Stage 2, well before a crisis point is reached. This is why California’s SB 553 mandates that employers train all employees — not just security staff — to recognize and report these signs.

What to Do When You See Warning Signs

Recognizing warning signs is only valuable if you know how to respond. Here’s what every employee should do:

Report It Immediately

Never assume someone else will report the behavior. Use your organization’s reporting channels — whether that’s a supervisor, HR department, anonymous hotline, or security team.

In California, your employer is required to have a reporting procedure as part of their workplace violence prevention plan. [INTERNAL LINK: /workplace-violence/]

Document What You Observe

Keep a factual record of what you saw or heard, including:

• Date and time
• Location
• What was said or done
• Who was present
• Any physical evidence (emails, texts, social media posts)

Don’t Confront the Individual

Unless you’re a trained security officer or threat assessment professional, do not attempt to confront the person directly. This can escalate the situation and put you at risk.

Trust Your Instincts

If something feels wrong, it probably is. Workplace violence prevention experts consistently emphasize that the biggest mistake people make is not reporting because they’re afraid of overreacting.

It’s always better to report and be wrong than to stay silent and be right.

The Role of Security Officers in Early Detection

Security officers are often the first line of defense against workplace violence. They interact with employees, visitors, and vendors daily, giving them a unique vantage point to observe warning signs.

At E3 Security Training Academy in Manteca, CA, our Workplace Violence Prevention training equips security professionals with the skills to:

• Identify behavioral red flags in real time
• Conduct preliminary threat assessments
• De-escalate volatile situations before they become dangerous
• Coordinate with HR, management, and law enforcement

Our BSIS-certified courses prepare security officers to go beyond basic guard duties and become proactive safety assets for their organizations.

California’s Legal Framework: SB 553

Since July 1, 2024, California’s SB 553 requires nearly all employers to:

• Develop and implement a written workplace violence prevention plan
• Train employees on the plan, including how to recognize warning signs
• Maintain a violent incident log
• Conduct periodic reviews and updates of the plan

This means that understanding warning signs of workplace violence isn’t just good practice — it’s a legal requirement for California workplaces. Employers who fail to comply can face citations and penalties from Cal/OSHA.

Build a Culture of Awareness

Preventing workplace violence isn’t just about policies and plans — it’s about creating a culture where employees feel empowered to speak up. Organizations that foster open communication, provide mental health resources, and take every report seriously are far less likely to experience violent incidents.

Key cultural elements include:

• Zero-tolerance policies for threats and intimidation
• Anonymous reporting systems that protect whistleblowers
• Regular training for all employees, not just security staff
• Employee assistance programs (EAPs) for those in crisis
• Leadership buy-in that prioritizes safety over convenience

Take the Next Step: Get Trained

Whether you’re an aspiring security officer, a current guard looking to advance your skills, or a business leader responsible for workplace safety, understanding warning signs of workplace violence is essential.

E3 Security Training Academy offers comprehensive Workplace Violence Prevention courses designed for security professionals and corporate teams throughout Manteca, Stockton, Modesto, Tracy, Lodi, and the greater Central Valley.

👉 Learn more about our Workplace Violence Prevention training or browse all available courses to find the right program for your career.

Don’t wait for a crisis to act. Get trained. Stay vigilant. Keep your workplace safe.