He was pulled over for driving erratically. It was then that police found Christmas had a suspended license and uncovered a 9mm semi-automatic handgun tucked under the driver's seat.
Christmas, a Philadelphia native, starred in Temple University's basketball team after attending Samuel Fels High School and Philadelphia Lutheran Christian.
He went undrafted by the NBA in June, but was invited to attend camp with the 76ers.
Christmas had just been cut on Wednesday.
Christmas is facing motor vehicle violations and weapons charges.
He was released earlier Friday morning after posting bail, but he will have to report back next week for a preliminary hearing.