The Broomfield Police Department has identified the suspect as Lawrence Raymond Crouch, 62, of Lakewood.
The Adams County Bomb squad also got involved in the situation. They blew up a suspicious device in the suspect's vehicle.
It all happened on the 100 block of Commerce Street around 2:30 p.m.
Officials closed area roads surrounding the incident as a precaution. Nearby businesses were also evacuated.
Crouch is being held at the Broomfield Detention Center on charges of murder in the first degree.