Prince George's County Corrections Department officials said yesterday they could not have prevented the suicide by hanging of a 25-year-old Northeast Washington man in the county detention center in Upper Marlboro Wednesday evening.

"Other than having someone standing in front of each cell, there was no way we could have prevented it," said corrections spokesman Jim O'Neill. "An officer [guard] saw him less than 10 minutes before and was never more than 50 feet away from him."

The suicide victim, Fred O'Neal of 3970 East Capitol St. NE, was awaiting trial on a charge of theft for allegedly stealing four packages of meat worth $30 from an Oxon Hill grocery store. He had attempted suicide in the jail three weeks ago, but a jail guard and a paramedic saved his life. After that attempt, on April 2, O'Neal was sent to a state mental hospital for evaluation and treatment. He returned to the jail last week and was placed in the jail's mental observation section, where guards check on prisoners more frequently than in other sections, according to spokesman O'Neill.

Unlike most other prisoners in the jail's mental observation section, O'Neal was in a cell by himself. Asked whether O'Neal could have been saved if he had had a cellmate, spokesman O'Neill said yes -- theoretically. He said the prisoner did not have a cellmate because "he assaulted other prisoners and threw urine and excrement on the officers [guards]."

The only thing that might have saved the prisoner's life, suggested spokesman O'Neill, would have been a policy of not putting mentally disturbed inmates in jail. "We do not feel jail is an appropriate place for emotionally disturbed people," said O'Neill. "We are trying to get a ward in a hospital to provide security for these people. People are not amenable to treatment when their freedom is denied."

Dr. Roland Vieta, the psychiatrist who evaluated the prisoner at the Spring Grove state hospital in Catonsville, Md., said he discharged O'Neal from the hospital because he provided him with medication -- thorazine -- designed to "control the psychosis. It's like insulin for a diabetic." Jail officials said O'Neal had been taking his medication.