SOMERVILLE, N.J. — The prosecution case against Jayson Williams got off to a rocky start Wednesday when the first two witnesses, a veteran state trooper and his rookie partner, offered very different accounts of the former NBA star's demeanor following the fatal shooting of a chauffeur at his mansion.

The older trooper, a 15-year veteran who knew Williams socially through his charity work with law enforcement, said the hoopster appeared sober, was upset about the shooting and seemed so concerned for the victim, Costas "Gus" Christofi, that he attempted CPR on his lifeless body.

But his partner, who was on the force less than a year and acquainted with Williams only through his TV appearances, told jurors the one-time All-Star stunk of alcohol, slurred his words, complained about his treatment by troopers and tried to discourage other witnesses from cooperating.

Trooper Thomas Muehleisen painted a flattering portrait of Williams.

That trooper, Melvin Saunders II, testified that Williams told his 11 houseguests "not to say anything because he had a lawyer coming."

Because Saunders and his more experienced colleague, Trooper Thomas Muehleisen, saw Williams at different times and held independent conversations with him, their testimony was never in direct contradiction. But their varying descriptions of Williams' behavior may have proved a jarring introduction for jurors.

The 35-year-old athlete faces 55 years in prison if found guilty of aggravated manslaughter and other charges stemming from the Feb. 14, 2002, killing. Prosecutors contend he was drunk and reckless when he toyed with a loaded shotgun in his master bedroom. The weapon discharged, hitting Christofi, 55, in the abdomen.

Williams is also accused of attempting to cover up his role in the shooting by staging the scene to look like a suicide and telling his guests to lie to authorities.

The sixteen jurors appeared to pay rapt attention as the troopers and another witness, a paramedic, described the scene at Williams' "Who Knew?" estate in the minutes and hours after the predawn shooting.

When Trooper Muehleisen demonstrated how he had examined the double-barrel shotgun found a few feet from Christofi in Williams' master bedroom, eight of the panelists stood up in the jury box to get a better view. One woman remained standing as prosecutors flashed photos of Christofi's body on a projector screen.

Muehleisen, Saunders and volunteer paramedic Matthew Wilson all said they were dispatched to the 40-room mansion in rural Hunterdon County for what 911 operators believed was a possible suicide.

Muehleisen said that, when he and Saunders arrived at the 40-room mansion just before 3 a.m., Williams led him straight to Christofi's body. As he tried to feel for a pulse, he said, Williams knelt beside him and "attempted to blow air into his mouth." He smelled no alcohol on his breath then, nor in subsequent conversations, although he did smell liquor when in the company of some of Williams houseguests, he testified.

Williams, though, "did not appear to be intoxicated to me," said Muehleisen.

A look at the gun

During a lengthy and friendly cross-examination, Muehleisen also said that he examined the shotgun found near the body. Its design made it difficult to see if the lower of its two barrels was loaded, he said. Prosecutors contend Williams knew the gun was loaded because he looked into the gun barrels before snapping the weapon shut, but Muehleisen's testimony appeared to undercut that.

"If you hold it like this, you can't see the final shell," he said, cracking the shotgun partially.

Muehleisen acknowledged that he attended a party Williams threw for troopers at his mansion before the shooting.

"Mr. Williams was friendly with troopers?" defense lawyer Michael Kelly asked.

"Yes," Muehleisen said.

"And you were friendly with him," the lawyer asked.

"Yes," the trooper replied.

Trooper Melvin Saunders II told jurors that, before the shooting, he had only seen Williams' home on "MTV Cribs."

Saunders, who drove to the scene of the shooting with Muehleisen, had a different story. Asked by prosecutor Steven Lember if he had ever visited the mansion, he replied, "Sir, I saw it on 'MTV Cribs.'"

He said he smelled alcohol on Williams' breath the first time he talked to him and noticed that his eyes were bloodshot and he was slurring his words. Later Williams griped to him about the troopers' activities.

"He advised that he felt as if we were treating him as a criminal," Saunders said.

"Were you treating him as a criminal?" asked Lember.

"Anything but, sir," Saunders replied, noting that he let Williams' wife and parents into the house to bring him pillows and comfort him.

Defense lawyer Kelly tried to shake Saunders' testimony with a painstakingly detailed cross-examination. He suggested the young trooper had focused on Williams before he was even a suspect and never noted the level of sobriety of any of his guests.

"No one else but Jayson this night is zeroed in on," charged Kelly.

"I don't think he was zeroed in on," Saunders replied.

Bloody shirt revealed

The third witness, Wilson, who examined Christofi's body, testified that he found a 2-inch-by-2-inch hole in his abdomen and a pool of blood under his body.

As prosecutor Katharine Errickson lifted Christofi's bloodied shirt from a bag from evidence, a young woman seated in a row reserved for the victim's family gasped and began sobbing. Jurors immediately turned and stared at her, prompting the judge to halt testimony and prosecutor Lember to speak privately to the woman. The woman later left court. No one connected to the case seemed to know who she was.

During Wilson's testimony, the courtroom lights were dimmed as photos of the shooting scene were flashed on a wall. The pictures showed both tragedy and wealth. Christofi, a limousine driver who had turned his life around after drug addiction and stints in prison, was crumpled on his side, dressed in gray pants and shirt. Beneath him was an ornate oriental rug and above him a glossy wooden table topped with an elaborate floral arrangement. The shotgun lay several lengths away on a highly polished hardwood floor.

Wilson recalled Williams entering the master bedroom and asking if Christofi was dead. Told he was, Wilson said, "He seemed irate and upset. More upset in a way. I believe he said, 'Oh, man' and kinda swung his head down and then he walked out of the room."

Surrounded by five lawyers at the defense table, Williams, dressed in a gray suit, appeared to be following the testimony very closely. He whispered to his lead attorneys, Billy Martin and Joseph Hayden, as the witnesses testified and seemed at times to be suggesting follow-up questions.

As he had Tuesday, Williams came to court sporting a diamond and silver cross on his lapel. A Brooklyn pastor, Rev. Herbert Daughtry, attended the trial in support of Williams and said he had prayed with Williams in a conference room near the courtroom Wednesday morning.