Somerville, N.J. ? Former NBA standout Jayson Williams killed a limousine driver while fooling with a shotgun, then tried to cover up his role by putting the victim’s fingerprints on the weapon, a prosecutor said in opening statements Tuesday at Williams’ manslaughter trial.

“This defendant took the hand of a dying man and attempted to transfer the fingerprints of a dying man to the gun,” prosecutor Steven Lember said.

Williams, 35, is charged in the death of Costas “Gus” Christofi, 55, who was killed in 2002 at Williams’ 40-room mansion.

Defense lawyer Billy Martin said the shooting by Williams — whom he referred to as “a big Teddy bear” — was an accident, and suggested the retired New Jersey Nets center would testify to that.

“Jayson Williams will tell you how this horrific, totally unforeseeable, accident occurred,” Martin said in his opening statement.

Prosecutors maintain while Williams did not intend to kill Christofi, he acted with reckless indifference when he took a 12-gauge shotgun from a cabinet in a bedroom and opened it and closed it in one motion. It fired and hit Christofi, who was about three feet away.

Anticipating the defense, Lember insisted the shooting “wasn’t any accident at all.” He added, “That shotgun could not have fired without the defendant’s finger on the trigger.”

Martin, however, said the shotgun had no safety and had a history of accidental discharge. He said evidence would show debris in the shotgun may have contributed to its firing.

In addition, Williams did not realize Christofi had walked into the bedroom and was in front of him, Martin said.

After Christofi was shot, “Mr. Williams panicked,” Martin said. “He instantly dove on the ground, trying to comfort Mr. Christofi.”

“Maybe he should have done some things differently, but he did not have criminal intent,” Martin said.

Prosecutors said Williams wiped the gun and tried to put the victim’s fingerprints on it, changed his own clothing, and told his guests to agree that the shooting was a suicide.

Martin said a Williams friend, Kent Culuko, who has pleaded guilty to evidence and witness tampering, suggested making it look like a suicide, and that he and others had adjusted their testimony after getting deals from prosecutors.

Williams faces eight charges, including aggravated manslaughter and witness tampering, that could carry up to 55 years in prison.