Updated
Under CRS Section 18-12-103, it is a Colorado class 1 misdemeanor knowingly to possess a defaced firearm. A defaced firearm is one on which the manufacturer’s serial number, or other distinguishing number or identification mark, has been removed, defaced, altered, or destroyed, except by normal wear and tear.
Possible punishment for possession of a defaced firearm in Colorado can include:
- 6 – 18 months in jail, and/or
- A fine of $500-$5,000.
This is separate from, and in addition to, any penalties you face if you are also found guilty of defacing a firearm, Colorado 18-12-104 C.R.S.

It is a Colorado class 1 misdemeanor to knowingly possess a defaced firearm.
Can possessing a defaced gun be charged as a felony?
Possession of a defaced firearm becomes a Colorado class 5 felony if within the previous 5 years you have a conviction for:
- Possession of a defaced firearm, 18-12-103 C.R.S.;
- Unlawfully carrying a concealed weapon, 18-12-105 C.R.S.; or
- Prohibited use of weapons, 18-12-106 C.R.S.
As a felony, penalties for possession of a defaced firearm can include:
- 1-3 years in prison (with 2 years mandatory parole), and/or
- A fine of $1,000-$100,000.
Moreover, you face collateral consequences of a felony conviction, including the loss of your federal and Colorado gun rights.
Defenses to possession of a defaced firearm
There are a number of ways to defend charges under 18-12-103 C.R.S. Our Colorado criminal defense lawyers can help you decide the best defenses to your charges of possessing a defaced firearm.
However, common defenses often include (but are not limited to):
- You didn’t know you had the weapon;
- The gun wasn’t yours;
- The serial number was legible;
- If the serial number was illegible, it was from normal wear and tear;
- The gun was found during an illegal search and seizure.
For additional help…

Call us for help…
If you or someone you know has been accused of possession of a defaced weapon or any other Colorado gun law, we invite you to call us for a free consultation.
To reach one of our knowledgeable Colorado defense lawyers, fill out the form on this page or call us at our Denver home office:
Colorado Legal Defense Group
4047 Tejon Street
Denver, CO 80211
(303) 222-0330