Federal investigators have found a culture of systemic abuse and neglect at one of Chicago’s most notorious prisons. In a new report, prosecutors found numerous cases of physical violence against prisoners by jail guards at Cook County Jail. Last year, a prisoner was handcuffed and beaten after he exposed himself to a female guard. In 2006, a prisoner’s leg was amputated after his infection went untreated. Prosecutors say they’ll take legal action unless conditions at Cook County Jail are drastically improved.