Pop singer Aaron Carter was arrested for investigation of marijuana possession Thursday after he was pulled over for speeding in Texas, authorities said. Carter, 20, the younger brother of Nick Carter from the Backstreet Boys, was in jail in Junction, Texas, awaiting a Friday morning appearance before a magistrate, Kimble County Sheriff Mike Chapman tells PEOPLE. Carter's Cadillac Escalade was pulled over for speeding in Junction at about noon on Thursday, said Chapman. Officers found less than 2 oz. of marijuana, the sheriff said. There was nobody else in the car. His arrest was first reported by TMZ.com.