The son of an inmate who died after a prolonged beating by New York prison guards said in a federal lawsuit Wednesday that his father’s attackers “systematically and casually beat him to death” in a correctional system that tolerates violence.

The videos show a brutal assault: In December, New York corrections officers beat, kicked and choked a handcuffed Robert Brooks, 43, inside the medical unit at Marcy Correctional Facility, near Syracuse. Hours later, he died from his injuries, authorities said.