A Tucson police officer was fired from the department Tuesday after being arrested for pulling a gun on a convenience store clerk, authorities said.

The officer, Kyle James McCartin, 23, is facing charges of aggravated assault and was booked into the Pima County jail. He was off duty at the time of the incident.

The Pima County Sheriff’s Department said two men — both wearing ballistic-type vests with no shirts underneath — walked into the Giant Gas Station in the 6800 block of East Sunrise Drive at around 3 a.m. Tuesday.

The two men appeared to be intoxicated, said Deputy Jesus Banuelos, a spokesman for the sheriff’s department.

During the sales transaction one of the men, later identified as McCartin, pulled a gun and aimed it at the clerk. The second man told that man to put the gun away but he again pointed it at the clerk.

The two men left on foot from the store, but were located a short time later at a nearby apartment complex.

Sheriff’s investigators said the man with the gun never made any demands of the clerk.

Sgt. Chris Widmer, a spokesman for Tucson police, said the department was notified about the incident and began an investigation.

After reviewing the case, Chief Roberto Villaseñor, decided to terminate McCartin, Widmer said.

McCartin was hired by the department last September and was still on probation.