Robert Mitchell, 58, of Hollywood, FL has no law enforcement affiliation, Detective Lt. Edward Kane said Tuesday.
Officer Kevin McWilliams approached the couple on Friday, then spotted a magazine that turned out to contain hollow-point bullets, the lieutenant said.
A search turned up the semi-automatic handgun and the “tactical” bag marked “POLICE” in large white letters, Kane said.
Mitchell also was carrying small amounts of pot and hash, he said.
His passenger had a small amount of marijuana, for which she was charged before being released on a summons.
Mitchell, meanwhile, was sent to the Bergen County Jail on various illegal weapons and drug charges, as well as impersonating a police officer.
A judge ordered that he remain held pending further court action following a detention hearing in Hackensack.
Click here to follow Daily Voice Northern Highlands and receive free news updates.