One of two males sought in connection with an execution-style slaying in Southeast Washington last week is awaiting trial on an unrelated homicide charge, police said yesterday.

Reginald "New York Reggie" Douglas had been arrested in connection with an August 1989 homicide. He was later released after posting a $75,000 bond, police said.

Douglas, 20, and David Long, 17, are believed to be part of a group that kidnapped Anthony Eugene Morrisey, of Northwest Washington, Wednesday night. The 20-year-old Morrisey was executed early Thursday morning behind the 100 block of 58th Street SE, where both Douglas and Long lived.

Police said the kidnappers, who demanded $20,000 and a kilogram of cocaine, included at least two other men whose names were not made public yesterday.

The case has become a sensitive matter for the D.C. police department because detectives became involved apparently hours before Morrisey was killed. An internal inquiry into how the matter was handled began Thursday, sources said.

The Morrisey family insists cocaine was never mentioned by the kidnappers, but police from the outset have said that Morrisey was involved with drugs.

Homicide Detective Dwayne Stanton said yesterday that Morrisey was killed because the kidnappers believed the ransom demand was not being met.

Douglas is awaiting trial in connection with the killing of Leon Anthony Lipford, who was shot in the 5300 block of Clay Terrace NE in August 1989. Police had no motive for the killing, and Lipford's age and address were not available late yesterday.

Police said anyone with information on the suspects should call the homicide division at 727-4347.