An inmate of the Arlington County Detention Center, who should have been under "constant or near-constant observation," tried to hang himself with a bed sheet in his cell several weeks ago and has been in a coma since then, Arlington Sheriff James A. Gondles said yesterday.

The attempted suicide of Brhan Alawte also called Brhane Habte , was not discovered for about 20 minutes after the Sept. 7 incident, Gondles said. Sheriff's deputies assigned to watch the man, charged with malicious wounding, did not notice that his cell door was closed, the light was off and a television monitor connected to the room had gone dark, the sheriff said.

Gondles said no information about the suicide attempt was released at the time because an examination of the deputies' actions that night began immediately afterward. "Some serious investigation took place in the sheriff's office. I don't feel I have the responsibility to call the media " to announce such an investigation of personnel, he said. That investigation was completed last week, he said. The incident was first reported in the Arlington Journal.

The incident "was just clearly a case of procedures and policies not being followed" by sheriff's deputies, he said.

Alawte, 35, was found about 12:30 a.m. when sheriff's deputy Edgar Lancaster walked by his special observation/isolation cell and noticed the door was closed and the light off, Gondles said. He said Lancaster opened the door, called a nurse on duty on the floor, and the two performed cardiopulmonary resuscitation on Alawte for about five minutes until a rescue squad arrived.

Two deputies in addition to Lancaster were on duty on the floor at the time, Gondles said, and "neither one is with the sheriff's office" now. He would not comment further on the two deputies' departures, which he said took place in the past two weeks.

Lancaster holds the same job in the sheriff's office he had before the incident, but Gondles said he "was not going to confirm or deny" whether any disciplinary action was taken against him.

Alawte, an Ethiopian refugee described by his court-appointed attorney as articulate and well-educated, had tried to hang himself in the jail once before, on April 29, while awaiting trial.

An Arlington psychiatrist who examined him shortly after that incident wrote, according to court documents, that Alawte "would remain a very serious suicidal risk at this time if returned to the Arlington jail."

Alawte was sent to Western State Hospital in Staunton, Va., wandered off the grounds June 11 and was returned to the Arlington jail about a month later, according to court records.

A psychiatric report dated Aug. 16 said that "after arriving back at the jail, Alawte again began to request isolation from the other inmates. This was the exact same behavior that had been a prelude to his previous suicide attempt."

On Sept. 6, Circuit Court Judge Thomas R. Monroe ordered psychiatric hospitalization for Alawte, and he was placed in the special observation cell for the night awaiting transfer to a hospital, Gondles said.

According to court documents, Alawte told psychiatrists he had no relatives or permanent address in this area. A psychiatrist's report said Alawte had been a street person for about four months prior to his arrest.

Alawte is listed in critical but stable condition in National Hospital for Orthopaedics and Rehabilitation in Arlington.