Dak Prescott's father was arrested for possession of marijuana over the weekend in Texas ... where he was forced to pose for a mug shot.
57-year-old Nathaniel Prescott was driving on Highway 87 in Orange County, TX -- about an hour and a half outside of Houston -- when he was stopped for a traffic violation.
During the stop, troopers discovered weed (less than 2 grams!) in the driver's side door of his Cadillac Escalade and arrested Prescott for misdemeanor possession ... a Class B offense.
Prescott was hauled to a nearby station where he was booked and posed for a mug shot. He was eventually released on $500 bond, according to KFDM's Peter Eliopoulos, who broke the story.
FYI, recreational weed is legal in 9 states. Medical is legal in 30 states.