In courtroom testimony yesterday disrupted by numerous objections from the defense, a 38-year-old Delaware man admitted driving his mother's car into North Philadelphia nearly two decades ago so a fellow skinhead could kill a black man.

Craig Peterson, 38, of Newark, pointed out Thomas Gibison, 35, also of Newark, as the man who shot Aaron Wood "between the eyes" as the victim stepped from between two parked cars on April 16, 1989.

Gibison has been charged with murder, ethnic intimidation and related offenses in the killing of Wood, 35, of North Philadelphia.

Peterson has been granted immunity in the case from prosecution by the federal government.

On the day Wood was killed, Peterson said he and Gibison drove to Wilmington in search of an African American to kill. But there were too many people around - Peterson referred to them as "witnesses" - so Gibison suggested that they drive to North Philadelphia.

Near Girard College, Peterson said, Gibison spotted a man walking down a dark one-way street and crossing toward their car.

Peterson, who was behind the wheel of his mother's Chevrolet Beretta, said Gibison told him "slow down," then leaned out of the passenger window and aimed a .38-caliber Colt revolver at the man's head.

"I heard him hit the ground with a big thud," Peterson said. Wood, a single father of five who did odd jobs and lived in the neighborhood, died at the scene of a gunshot to the head.

Peterson said the killing was done so Gibison could legitimately sport a spider-web tattoo over his left elbow. In some white supremacist circles, such a tattoo indicates that the bearer has killed an African American.

The witness then displayed his own spider-web tattoo, and told the jury that he and Gibison had awarded themselves the markings to tout their commitment to the "white-power skinheads."

Peterson said he had known Gibison since they were in fourth grade and that the two became skinheads together.

"He was like my brother," Peterson said.

Gibison was impassive throughout his former friend's testimony, staring straight ahead or conferring with his lawyer.

Tempers frequently flared in this third day of testimony before Common Pleas Judge M. Teresa Sarmina, with defense attorney J. Michael Farrell throwing numerous objections to Assistant District Attorney Roger King's prosecution of the case.

Farrell attempted to punch holes in Peterson's testimony by trying to elicit admissions from the witness that he had told investigators what they wanted to hear to avoid prosecution.

Peterson said that when federal investigators - following up on a tip from the accused's former girlfriend - began asking about the case two years ago, he lied to them.

But when he was confronted with the prospect of having to testify before a grand jury, Peterson confessed his role in the killing and agreed to testify. He said he had already gone to jail once for lying to a grand jury.

"I didn't want to go to jail again," Peterson said.