LAS VEGAS, N.M. - Authorities say a man driving a truck with police lights on top made a crucial misstep during a bogus police stop in northern New Mexico.Police say the two men he pulled over for speeding were real state police agents in an unmarked vehicle.According to New Mexico State Police, 26-year-old John Shelton, of Logan, was arrested Wednesday following the sham traffic stop in San Miguel County.Investigators say Shelton had a pistol on his hip and told the agents he was a member of the New Mexico State Police Search and Rescue and a trained law enforcement officer — something officials later discovered wasn't true.Shelton is facing charges of impersonating an officer.It was not clear if Shelton had an attorney.