In the world of racist skinhead Tom Gibison, killing a black man deserved a trophy.

At his girlfriend's prom in 1989, then-17-year-old Gibison decided to prove to a guy he had just argued with just how tough he was.

"Off comes the coat, [and Gibison is] showing a spiderweb tattoo [on his elbow]," Assistant District Attorney Roger King told a jury of four black and eight white jurors during opening arguments yesterday.

" 'You know what this means? I killed a black guy,' " King quoted Gibison as saying.

Describing the murder as an "assassination," "senseless" and "cold-blooded," King said the victim, Aaron Wood "was singled out and killed just because he was a black man."

"Little did we know at the time, this could be declared a hate crime," he said of the 1989 murder. "Justice grinds slowly."

Yesterday, Gibison's racist tattoos were hidden from view. The fist tattoo on the top of his head was covered by light brown hair. A blue-striped shirt covered the spiderweb on his elbow and other tattoos on his neck and elsewhere.

The 36-year-old Newark, Del., man sat with his hands folded, expressing no emotion, at his trial on charges of murder, criminal conspiracy, ethnic intimidation and weapon offenses.

Common Pleas Judge M. Teresa Sarmina, who is presiding over the trial, expected to last a week, issued a gag order to prevent the attorneys from discussing the case.

King said that at 12:40 a.m. on April 16, 1989, Wood, 34, stepped off the curb between two parked cars on Stillman Street near Ingersoll in North Philadelphia.

"There's one there," shouted Gibison from a gray Chevrolet Beretta driven by his best friend, skinhead Craig Peterson, who had just driven north from Wilmington, where they couldn't find blacks to kill.

"Tom shot him one time right between the eyes," said Peterson, according to King.

Gibison would later describe to a girlfriend the sound of the victim's head hitting the pavement, King added.

Seventeen years later, investigators from the Wilmington police force; the Bureau of Alcohol, Tobacco, Firearms and Explosives; the FBI, and Philadelphia police pieced together the whodunit with the help of Gibison's two ex-girlfriends, that spiderweb tattoo and a co-conspirator.

"Isn't it a sad commentary that Mr. Warner is dead because he was there in a neighborhood - a neighborhood that was not posh, not ritzy," the prosecutor added. "It came down to a killing based on race: willful, deliberate and premeditated."

Not so, argued Michael Farrell, Gibison's attorney, who offered an alternative theory of Wood's murder.

Although he admitted this was a race-charged case, Farrell said that at 17, Gibison was a "blue-collar skinhead," not a racist. He believed in "America first," when he obtained a fist tattoo on the top of his shaved head.

"Guns and drugs are responsible for the murder of Aaron Wood, not Tom Gibison," said Farrell. "In 1989, guns and drugs caused more murders in this city than in any other years."

Farrell contended that Wood had been "a drug dealer who received cocaine and didn't pay for it and owed thousands of dollars" for drugs.

"A hit man even called his girlfriend to threaten Aaron Wood, who had not paid the debt five months before he was struck down on the street," said the defense attorney.

Farrell said a witness, Edward Butts, who was at 25th and Thompson, two blocks away, would testify that he had seen three black men running from the murder scene.

Gibison was not arrested until November 2006 - not 1989 - and he blamed the arrest on a "scorned girlfriend" who was upset that he was seeing other women when she wanted to be his wife.

Farrell contended that a package of cocaine and $20 had been hidden in Wood's left sock, but homicide Detective George Pirrone, a patrolman in 1989, testified that socks had been listed on a receipt he turned in, but not cocaine. *