The officer was sitting in his own vehicle at Carl’s Jr. at around 3:30 a.m. when the suspect approached him, KKTV-TV reported. It is not clear whether the suspect reached for a gun or fired one.

The officer fired at least once and was not injured, police said. The suspect died at the scene.

Police are investigating whether a person involved in an armed robbery at a nearby gas station before the shooting was the man who was killed at the drive-thru.

The shooting itself is being investigated by the El Paso County Sheriff’s Office.