A man was arrested on Thursday on suspicion of impersonating an officer with the Mesa (AZ) Police Department.

According to the Arizona Republic, the man—identified as 28-year-old Joshua Hillman—was taken into custody by the Arizona Department of Public Safety after a trooper stopped to assist with what he initially thought was a legitimate traffic stop.

The trooper quickly became suspicious when he noticed that the individual conducting the stop was not wearing a sidearm.

Hillman was arrested and booked into jail on suspicion of impersonating a police officer and three counts of kidnapping.