A 21-year-old man who police said fatally stabbed his former 72-year-old roommate was paid by his victim for sex, a homicide detective testified Wednesday in D.C. Superior Court .

David J. Wilson has been charged with second-degree murder in the killing of Howard Venable Jr. in Venable’s Northwest Washington apartment on Feb. 1 .

At Wilson’s preliminary hearing Wednesday, D.C. homicide detective King Watts testified that Wilson and at least one other witness told authorities that the two men were involved in a relationship in which Venable would pay Wilson for sex every two weeks. Hours before Venable was killed, one witness told authorities, the two men were exchanging text messages about Wilson bringing over “ice cream.” That, Watts said, was code for sex.

Venable’s body was found face down in the hallway of his one-bedroom apartment. His throat had been slashed, and he suffered three stab wounds to the chest.

Watts did not offer a motive for the killing, and a weapon has not been found.

Until a few days before Venable’s death, according to testimony, the two men lived together in Venable’s apartment in the 1600 block of Fuller Street NW on the edge of Adams Morgan and Mount Pleasant. Wilson, according to his attorney, had moved out of the apartment and back into a District Heights apartment he shared with his wife and three young children.

According to charging documents and testimony, Wilson met voluntarily with police on Feb. 3 and was arrested after four hours of questioning. Wilson initially denied knowing Venable and then cried when he was told that Venable had been killed, Watts said. Wilson then offered three scenarios to detectives, claiming at one point that robbers broke into Venable’s home. He also said that he and Venable wrestled over the knife and that Venable accidentally stabbed himself, according to the documents.

Watts testified that there were no signs of forced entry or a struggle. Blood was splattered on the hallway wall above where Venable’s body was found.

A security tape, according to testimony, showed Wilson using Venable’s bank card at a gas station in District Heights. Wilson’s public defender, Jacqueline Cadman, argued that Venable was alive at the time her client was videotaped using the bank card.

Cadman argued that Venable and her client had been in a long-term, abusive sexual relationship since Wilson was a “child” and that because of the abuse, the charges should be reduced to manslaughter. Judge Stuart G. Nash denied Cadman’s motion, saying it was the wrong hearing for that type of argument. He called Venable’s death a “particularly brutal murder” and ordered Wilson to remain in the D.C. jail until trial. Wilson’s next hearing is scheduled for May 10.

Venable, a retired security officer who was a widower and the father of three adult children, was an usher at the Cathedral of Christ Baptist Church in District Heights, according to church members who attended the hearing.

After the hearing, Venable’s sister, Susie Smith of Baltimore, said Wilson lied about the sexual relationship. She said her older brother had been trying to help after Wilson was released from a halfway house. Wilson had been charged with armed robbery in August but the case was dropped in January, the prosecutor said.

“My brother was just trying to help him when he didn’t have any place else to go,” Smith said. “He helped everybody.”