An inmate was found hanging in the Suffolk County Jail.

Julio Rivera was found at 11:53 p.m. Monday during a bed check, according to Chief Alan Otto of the County Sheriff's Department.

Rivera was arrested last year and charged with killing his 5-month-old son. Prosecutors believe Rivera shook the baby violently and blew smoke from a cigarette laced with PCP into the child's mouth to quiet him down.

Chief Otto says an investigation into the suicide is underway.