A Houston man was arrested after investigators say he posed as a police officer and pulled over a driver.

The driver was an off-duty sergeant with the  Harris County Precinct 6 Constable's Office.

According to deputies, the sergeant didn't stop on I-10 eastbound at Lockwood Drive and followed the fake cop west towards downtown Houston.

The cop impersonator used flashing lights when he tried to pull over the sergeant, investigators said.

The man was arrested in the Heights on West 20th Street and Rutland Street and charged with impersonation of a police officer.

The suspect told officers he just took an emergency responder class and thought he could pull people over, deputies said.