D.C. Police Officer Charles A. Dyson found the body of the homeless man sprawled on a mattress in an abandoned house downtown. The man had been stabbed repeatedly. There was no weapon, no witnesses, no apparent motive, no clues.

Ordinarily, Dyson, 41, a veteran patrolman, would have left the case to homicide detectives, but Dyson stayed with it "because of my contacts in that neighborhood . . . . Homeless people know what's going on in the street. The people in that neighborhood know and trust me, and I felt that I could help find the killer."

Eleven months after the murder, Wordell Johnson, 27, of 534 Fourth St. NE was convicted in the case thanks largely to Dyson's knowledge of the neighborhood, according to the U.S. Attorney's Office.

"Without his contacts in that neighborhood, we may have never located the eyewitnesses to that vicious homicide," said Assistant U.S. Attorney William A. Martin, who prosecuted the case.

Dyson was one of 65 law enforcement officers, including FBI and IRS agents, honored recently by the U.S. attorney's office at its Sixth Annual Law Enforcement Awards Ceremony.

Among the D.C. officers receiving awards were those who had solved the murder of Catherine Fuller, a Northeast Washington woman killed by a gang in an alley, and the kidnaping and murder of Arthur Gluckman, a U.S. Tax Court law clerk.

Dyson recalled that he became involved in the case Jan. 5, 1985. He and another police officer were walking their downtown beat when a homeless man stopped and told him that he had seen a body in a vacant building at 809 Fourth St. NW.

The three went to the house, entered the back door, went to the front of the house and found the body of a man surrounded by dirt and debris.

"I was surprised that the body was there . . . . There was a lot of blood on the body," Dyson recalled during an interview at the 1st District headquarters in Southwest.

Dyson and the other officer sealed off the house and called homicide detectives.

For the next few days Dyson combed the neighborhood, talking to men standing on street corners, looking for anyone who might know something about the death of the man who was later identified as Charles Harrison, 45. He had been living at the shelter for the homeless at Second and D streets NW.

Dyson had little success. Then, while he was at D.C. Superior Court on another case, on Jan. 10, he met a homeless man he knew, Michael Sothern.

Striking up a conversation, Dyson casually asked him whether he knew anything about the stabbing. Sothern first said no, but at the beginning of a second conversation, "His first words were, 'I was there,' " Dyson said.

Then, "Sothern hesitantly told me that the guy who committed the murder was a very mean person who carried a knife. He didn't want to say more. I reassured him that nothing was going to happen to him," Dyson said.

Then the story tumbled out.

Sothern and several of his friends went to a liquor store at Third Street and Massachusetts Avenue NW to buy wine. Then they went to the house on Fourth Street where Harrison and Johnson started arguing. Johnson said Harrison owed him money. During the argument, Johnson took out a knife and stabbed Harrison in the chest. Sothern said he left the house.

Dyson and other police officers searched for Johnson for 2 1/2 weeks. "He usually hung around Fifth and K streets NW so we concentrated our efforts on that area.

"We had pictures of him on file which were distributed," Dyson said.

Johnson was arrested Feb. 25. In December, Johnson was convicted of first degree murder while armed and obstruction of justice, according to court records.

"This case was the most rewarding in my career," Dyson said with a smile.