A New York state oversight panel wants federal prosecutors to probe the 2013 death of a mentally ill Rikers Island inmate who was locked in his cell for six days without care or medication.

A report obtained by The Associated Press calls Bradley Ballard's treatment "so incompetent and inadequate as to shock the conscience."

Ballard suffered from paranoid schizophrenia and had diabetes. State investigators found he sexually mutilated himself while locked away for making a lewd gesture at a female guard.

Investigators found dozens of jail guards and health workers passed by Ballard's cell but none helped.

A spokeswoman says the U.S. Department of Justice will review the report.

City officials say a mental health unit chief was transferred after Ballard's death and workers have been retrained.