Police had not found the 21-year-old by early Sunday, and were fearing for his safety.
The man was brought to a south Los Angeles station on Friday for questioning in an ongoing investigation.
About 6:15 p.m. , an officer walking through the hallway noticed his dangling body and called for help. A nearby LAPD officer and a nurse swiftly opened up the locked cell door and helped lift the man up before a sergeant could cut him free from the noose.
The man appeared to have created the noose from his shirt ribbing and tied it to a metal fire sprinkler near the center of the cell's ceiling.
"We are making hourly checks at his residence and locations he's known to frequent," said Detective Paul Scire on Saturday night. "We hope to locate him to get the mental health (care) he needs. I think if the hospital would have just called the psychiatric response team, this could have been prevented."
Police say hospital officials discharged him less than two hours later without seeking additional medical help for him.