If there’s one phrase that shows up in almost every self-defense law, it’s this:
“The defendant reasonably believed…”
But what does reasonable belief actually mean under Colorado law? And how does it affect whether your use of force is justified?
Whether you carry concealed, work in armed security, or just want to protect your home and family, understanding this legal standard is crucial. Because in a courtroom, it’s not just what you believed—it’s whether your belief was reasonable to others.
🔹 What the Law Says
Colorado law doesn’t protect just any use of force. It protects people who use force based on a reasonable belief that it’s necessary to defend themselves or someone else.
Under C.R.S. § 18-1-704:
You are justified in using force if you reasonably believe that force is necessary to defend against the imminent use of unlawful force.
This standard applies whether you’re using physical force or deadly force—but the consequences are a lot more serious when a firearm is involved.
🔹 Reasonable Belief vs. Actual Threat
One of the biggest misconceptions is that the threat has to be real.
Not true.
What matters is whether you believed it was real, and whether a reasonable person in your situation would have believed the same.
For example:
- If someone reaches into their waistband and makes a sudden move, and you think they’re pulling a weapon—that might be a reasonable belief, even if it turns out they were unarmed.
- But if someone just yells at you from across a parking lot, and you shoot them without any movement toward you or clear threat—that’s probably not reasonable.
🔹 How Courts Decide What’s “Reasonable”
Colorado courts use the “reasonable person” standard. That means your actions are judged based on what an average, rational person would have believed in your exact situation, including:
- The environment (e.g. dark alley vs. shopping mall)
- The history between you and the other person (if known)
- The speed and intensity of the threat
- Whether you tried to de-escalate or retreat
- The other person’s size, weapon, or actions
They do not evaluate your actions with perfect hindsight. They’re supposed to evaluate them from your perspective at the time—but through the lens of what a reasonable person would do.
🔹 Real-World Example
Let’s say someone aggressively confronts you in a parking lot, screaming threats and quickly reaching into their coat. You shoot, fearing they’re pulling a gun. It turns out they were just grabbing a phone.
If a jury believes your fear was reasonable under the circumstances, your use of deadly force could be justified—even though the person wasn’t actually armed.
Now flip the scenario: If someone is yelling but clearly walking away, and you shoot them in the back? That’s not a reasonable belief of imminent danger. You’re now facing a criminal charge.
🔹 How to Build Reasonable Belief Into Your Training
- Practice real-world judgment—not just marksmanship.
- Use scenario-based training that forces you to evaluate threats quickly.
- Learn to articulate what you saw and why you acted. This is what you’ll be doing if you’re ever in court.
- Know the law. You can’t form a legally reasonable belief if you don’t understand what the law actually says.
🔚 Conclusion
Self-defense law doesn’t expect perfection—but it does expect reasonableness. Your ability to recognize, assess, and respond to a threat appropriately will make or break your legal defense if you ever use force.
That’s why we say: If you carry, you must also carry the judgment to know when and why to use force. Understanding “reasonable belief” is where that starts.
Disclaimer: This article is for informational purposes only and does not constitute legal advice. For legal guidance, please consult a licensed Colorado attorney.
