An 18-year-old Alexandria man pleaded guilty yesterday in Fairfax County Circuit Court to the murder of a man he said he shot just after the two had homosexual relations in the victim's bedroom.

Clydel D. Diggs said in a statement to police that he shot David Thomas Jr., 48, on Oct. 28 "to see what his reaction would be," according to court records.

Judge Lewis H. Griffith accepted Diggs' guilty pleas to charges of murder and use of a firearm. Under Virginia law, the sentence for murder ranges from 20 years to life in prison. The firearms charge carries a mandatory two-year prison term.

Diggs went to Thomas' apartment with the intention of robbing him, according to Diggs' statements to police. After the shooting, Horan said, Diggs apparently took Thomas' wallet containing an estimated $25, his car keys and his car. "It looks like he was killed for $25--tops," Horan said after the hearing.

On the day of the murder, according to court testimony, Diggs arrived at the Sulgrave Manor Apartments in Mount Vernon with three other acquaintances, who waited outside in a car while Diggs entered Thomas' apartment.

After Diggs and Thomas engaged in sex, Diggs pulled out a .32-caliber revolver he apparently had hidden under a pillow. "I put a pistol to David's head," Diggs said in a statement to police. When police asked why he pulled the trigger, Diggs replied, "I guess to see what his reaction would be," according to court records.

Diggs told police he knew the pistol was loaded, but did not know if there was a bullet in the chamber when he pulled the trigger. Judge Griffith set sentencing for April 29.