Horton was charged with aggravated assault, resisting arrest, disorderly conduct and public drunkenness.
Horton was suspended indefinitely, the school announced Monday. Pitt is scheduled to open the season on Tuesday night against The Citadel.
According to public safety records, Pittsburgh Police responded to reports of an altercation just after 1 a.m. ET Saturday, after a tow truck driver called police. Horton was angry his car was being towed. Following a conversation with police, Horton "punched a responding officer in the face, causing a laceration to his lip," records show.
Court documents obtained by the Pittsburgh Post-Gazette specify that Horton allegedly hit the officer with his cellphone. Horton ran from the officer before being arrested and taken to Allegheny County Jail.
A 6-foot-3 guard, Horton is Pittsburgh's leading returning scorer after averaging 8.9 points per game last season. The New Jersey native began his career at Delaware, where he averaged 13.2 points per game in 2018-19 before transferring to the Panthers.
Horton's arrest comes days after Nike Sibande, who was expected to start alongside Horton in Pitt's backcourt, was lost for the season after tearing his right ACL in a preseason game.