A man pointed a gun at an officer and pulled the trigger but the firearm didn't discharge.
It happened Sunday morning at 7:41 a.m. at the Port of Entry (POE) in Fort Collins, according to the Colorado State Patrol.
Investigators say the suspect climbed into a very dirty white semi-tractor towing a white box trailer and headed southbound on Interstate 25.
The suspect is described as a light-skinned black or Hispanic male in his early to mid-30s, 5'7" to 5'9" tall, with short black hair, a mustache, and a medium build. The suspect was last seen wearing a light-colored short-sleeved shirt, blue jeans, and wraparound sunglasses.
The semi-tractor is reported to have the numbers "4177" behind the passenger-side door. The numbers may be part of a larger number.
Anyone with information about the incident, the suspect, or the vehicle should contact Officer Wes Haynes at the Fort Collins Police Department at 970-221-6540.