SOMERVILLE, N.J. — Jayson Williams had an arsenal of guns and ammunition in his bedroom the night he fatally shot a driver, a crime scene detective testified Wednesday at the former NBA star's manslaughter trial.

The firearms cache Williams kept in the spacious master bedroom of his lavish mansion included four 12-gauge shotguns and a high-powered hunting rifle in addition to the 12-gauge shotgun that killed chauffeur Costas "Gus" Christofi, according to a state police detective who was first to arrive on the scene.

Detective Christopher Wagner testified that three of the five weapons remaining in Williams' gun cabinet that night had live rounds in their chambers.

The fact that those weapons were loaded could be important evidence for prosecutors as they try to convince a jury Williams, a skeet shooting enthusiast, was well aware he was engaging in dangerous, risky behavior when he pulled the shotgun from the cabinet and began toying with it in front of the driver and several houseguests.

The 35-year-old could face 55 years in prison if convicted of aggravated manslaughter and other crimes related to Christofi's death.

The one-time New Jersey Net center insists the shooting was an unintended accident and should be treated as a civil matter, not a crime. He has paid the victim's family a reported settlement of $2.75 million.

As the 12 women and four men of the jury watched intently, prosecutor Steven Lember hoisted each of the six weapons to Detective Wagner, who held them out toward the jury box and identified them. The prosecutor announced at the start of court that, for the safety of everyone in court, each weapon was outfitted with a trigger lock.

Detective Wagner also identified 47 rounds of live ammunition found in a shooting vest near the gun cabinet.

A bloody shirt, pocket change

Wagner was on the stand for most of the day offering jurors a grim litany of the approximately 60 pieces of evidence he collected at Williams' mansion and during Christofi's autopsy.

Among the items he catalogued for jurors was the body bag, an empty box of shotgun shells, Christofi's blood-stained shirt and the 12 shotgun pellets the coroner removed from his abdomen during the autopsy.

In one of the more poignant moments of testimony in the trial so far, the detective matter-of-factly listed the personal effects removed from the body of Christofi, a 55-year-old bachelor. As Christofi's sister, Andrea Adams, looked on from the front row of the court gallery, Wagner held up his cellphone, house keys, quartz watch, a cross necklace and even the loose change from his pockets. The contents of his wallet, Wagner said, were several pieces of identification and $28.

Prosecutor Steven Lember (left) holds up the victim's bloody shirt for Detective Christopher Wagner to identify.

Another crime scene detective, John Ryan, told jurors he found Williams' full-length leather coat in the van Christofi was driving that night. In the wallet, Ryan testified, were several pieces of identification and $2,310.

Defense lawyer Joseph Hayden asked Judge Edward Coleman to prohibit prosecutors from showing a photo of the cash to jurors, saying the detective's words were sufficient and the picture suggested there was something wrong with having the money. He noted that the amount might seem especially distasteful to jurors who had recently heard about the more modest contents of Christofi's wallet.

"We don't need the juxtaposition," said Hayden.

But Coleman allowed the photo, saying of Williams, "The jury is aware looking at photographs of his house that he is a wealthy individual."

Dressed in a dark gray pinstriped suit and scarlet tie, Williams appeared to pay careful attention to the officers' testimony. As photos Ryan took of the mansion interior flashed on the screen, he whispered to the five attorneys on his legal team.

During cross-examination of the two detectives, Hayden and co-counsel Billy Martin tried to paint the officers and their investigation as unprofessional, suggesting they focused on Williams and his wealth and fame from the start.

Martin pointed out that Wagner had stored Christofi's bloody shirt in a white pizza box rather than an evidence envelope.

"Would you tell this jury why Mr. Christofi's shirt is in a pizza box," Martin boomed at the detective as he held the box out toward jurors.

Wagner said he chose the box, which he said had never been used for food, because he felt its shape would better preserve the hole in the garment than a bag.

Photographing the mansion

Cross-examining Ryan, Hayden showed jurors dozens of photos taken by the detective in Williams' 40-room home. Each of the photographs showed portions of the home not related to the shooting, including several guest bedrooms, bathrooms, a movie theater and a home office decorated with snapshots of relatives and other athletes.

The attorney suggested Wagner took the photos not to investigate a crime, but to pry into the personal life of Williams and his wife, Tanya.

Police photographed every part of the mansion, including the pool filter closet.

Pointing to a photo of a concrete wall in a swimming pool utility closet, he asked Wagner incredulously, "You felt that somehow the pool filter closet might be of some evidentiary value down the road?"

"Yes," the officer replied, adding that he documented every room in case it later became important.

A visibly agitated prosecutor, Katharine Errickson, bristled at the implication that investigators were snooping into the family's private business, pointing out that it was Williams' own defense, not prosecutors who displayed the photographs to jurors.

Testimony will continue Thursday morning.