PITTSBURGH, PA – A total of seven guards at Pittsburgh’s state prison surrendered last week on charges that they conspired in a wide range of prisoner abuse, including scenarios in which one would act as a lookout while others assaulted inmates in their cells and threatened further harm to keep them quiet.

According to the Pittsburgh Post-Gazette, the charges are the result of a grand jury investigation into the sexual and physical abuse of inmates at State Correctional Institution-Pittsburgh.

The charges against the guards, all of whom have been suspended without pay, stem largely from the accusations of inmates who testified they were subjected to or witnessed the abuses and were threatened to keep quiet. Attorneys for the guards say their clients are innocent and called their inmate accusers’ credibility into question.