A debt collector who fatally shot three co-workers at a savings and loan bank before killing himself had spent five years in a mental hospital after allegedly asking a police officer to shoot him, a state health official says.

Emanuel Tsegaye, 33, of Silver Spring, Md., argued with a supervisor Wednesday, left work and returned with .38-caliber revolver concealed in an athletic bag, police said. A fourth employee was shot in the jaw, police said.Tsegaye, a native of Ethiopia, had been a collector reportedly since October in the Visa card department of the Chevy Chase Federal Savings Bank in this Washington suburb. The shootings began in the seventh-floor office where he worked - a large room in which about 75 employees are grouped and separated by 6-foot partitions.

Officer George Ludington, spokesman for the Montgomery County police, said Tsegaye was a "disgruntled employee" but would not elaborate. He said detectives were still piecing together the motive.

A spokesman for the Maryland State Health Department said, however, that Tsegaye had been released about a year ago after five years at the Clifton T. Perkins Hospital Center in Jessup, Md.

Tsegaye was sent to the mental hospital after he was ruled criminally insane following his arrest on charges of assaulting a police officer, the spokesman, Mike Golden, told WUSA-TV in Washington.

"All of the people that I have talked to about it are very disturbed, very surprised by it . . . because all indications were that Mr. Tsegaye was doing very well," Golden told the station.

The station said Tsegaye had originally been arrested after approaching a Montgomery County police officer and saying, "I want to die, kill me," and then reaching for the officer's gun. He was charged with attempted murder in that case, according to the television report.