A HOMICIDE detective yesterday testified to some "bizarre" behavior by a murder suspect who was being questioned about his stepfather's shooting death in October.

Detective Brian Peters testified that during questioning, James Kelly was acting childish, then "offered to fight me" and offered another detective $50 to fight.

At one point, Kelly kept standing up and threw his fist into the air, as if punching, Peters demonstrated to Municipal Judge James DeLeon.

Kelly, 23, is accused of killing his stepfather, Rafael Santiago, 41, in their home on Holly Road near Woodhaven in Northeast Philadelphia about noon Oct. 5.

Peters, testifying at Kelly's preliminary hearing, said that when he went to the house about 4 p.m., he saw Santiago in a second-floor front bedroom, shot in the face. In a back bedroom, which was Kelly's room, Peters said, he saw a .22-caliber rifle and bullets.

Under questioning by Assistant District Attorney Peter Lim, Peters said he learned from people in the neighborhood that Kelly and his stepfather were having problems and that Santiago wanted his stepson out of the house. Kelly's mother also lived there.

About 11:30 that night, Peters said, when he and another detective began questioning Kelly in the Homicide Division, Kelly said he hadn't been at home when the shooting happened.

At some point, Kelly became aggressive and said to Peters, " 'You will be the second person I kill today,' " Peters said, adding that Kelly still wasn't saying if he had killed his stepfather.

After about two hours of questioning, Peters said that detectives decided to leave Kelly alone in the interview room for several hours.

During a second round of questioning that began about 10:30 a.m. Oct. 6, Peters said, Kelly admitted killing his stepdad. " 'I can't tell you why I killed him, I can't tell you why,' " the detective recalled Kelly saying.

Peters also testified that during the hours-long break, Kelly had punched the wall of the interview room, then written on the wall: "Kill Popeye." The detective said Santiago was known as Popeye.

(Kelly allegedly wrote the words using a piece of the drywall that he allegedly punched out.)

During questioning by Stephen Gross, one of Kelly's two public defenders, Peters acknowledged that none of Kelly's alleged comments was noted in any formal statement. Rather, Peters said, he typed in Microsoft Word what Kelly said as part of a summary of what happened, and then gave it to the assigned detective.

Helen Levin, Kelly's other lawyer, argued before the judge that her client's alleged comments would be "inadmissible" at trial. "It really does not indicate he did this shooting," she said.

Lim argued that although the case is based on circumstantial evidence, three people were in the house when cops arrived - the slain man, Kelly and Kelly's mother. He noted as evidence the rifle and bullets in Kelly's room, Kelly's remarks to cops and his writing on the wall.

The judge, in holding Kelly for trial on charges of murder and possession of an instrument of crime, said he was looking at the "totality of circumstances."

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