When reached, a University of Alabama Police Department spokesperson said he had no information on the arrest.
Williams, a senior, has started every game this season and has 1.5 sacks. He is currently the No. 9 prospect on Mel Kiper Jr.'s Big Board of draft eligible players.
The 6-foot-4, 237-pound Louisiana native came on strong as a junior in 2015, getting 10.5 sacks sacks despite not starting a game.
He is the second Alabama player who has been arrested for a charge involving a gun this year. Offensive tackle Cam Robinson faced felony gun charges during the offseason, but the district attorney declined to prosecute.