KINGWOOD, N.J. (AP) -- Former NBA star Jayson Williams surrendered Monday and was charged with manslaughter in the shotgun slaying of a limousine driver at his mansion. The 34-year-old NBC sports commentator used a back entrance into the state police barracks, and had no comment as he entered or left the building. He was freed on $250,000 bail. If convicted, Williams could face five to 15 years in prison. Costas Christofi, 55, was found shot to death at Williams' 65-acre estate in Alexandria Township on Feb. 14. Published reports have said Williams was playfully twirling a shotgun while giving a tour of his mansion when the weapon went off. Acting Hunterdon County prosector Steven Lember declined to comment on details of the shooting Monday. "The death of Mr. Christofi was a tragic accident, but it was an accident," Williams' attorney Joseph Hayden said. "We are very confident that after a full, fair and thorough exploration of all the facts it will be clear that Mr. Williams is innocent of recklessness and innocent of any criminal conduct." Initially, some of his guests reported the death as a suicide. After an autopsy, the medical examiner ruled the shooting a homicide. "We are most interested in getting to the truth in this case. Those witnesses should come forward and do the right thing. If they do, they have nothing to be concerned about," Lember said at a news conference Monday. Earlier, Lember told the New York Daily News that his office also was investigating whether Williams allowed Christofi to bleed to death before authorities were notified. Hayden has denied there was any horseplay prior to the shooting, and has not commented on who was holding the gun. Christofi had been hired to drive Williams' friends from a charity event in Bethlehem, Pa., to Williams' home, about 30 miles northwest of Trenton. The 6-foot-10 Williams was once among the NBA's best rebounders, but leg injuries ended his basketball career. He retired from the New Jersey Nets in 2000 and now works for NBC Sports as an NBA studio analyst. "We've been unable to get in contact with Jason's representatives and feel it's inappropriate to comment until we do so," NBC Sports VP Kevin Sullivan said. Williams, 34, has freely admitted past mistakes, describing them in a 2000 autobiography as 'a lot of beers and barroom brawls and some scrapes with the law and too many fights and some yelling matches with coaches and a bunch of headlines.' In 1992, he was accused of smashing a beer mug over a patron's head at a Chicago bar. Two years later, he was accused of firing a semiautomatic weapon into the parking lot at the Meadowlands sports complex. He wrote in his autobiography that he almost shot New York Jets wide receiver Wayne Chrebet while firing a shotgun on his skeet-shooting range. And Williams faces a hearing this week on a charge that he pushed a police officer last November in a New Jersey bar.