RIVERHEAD - The ex-con accused of gruesomely killing a friend and then going about his life while the corpse was stuffed in his bedroom closet pleaded not guilty in court today.

Prosecutors say Aston Barth, 33, killed his longtime friend and next-door neighbor, Jason Campbell, in Central Islip last month. Barth admitted killing Campbell to police, but prosecutors noted in court today that some details given by Barth don't exactly match up with the autopsy results.

Barth told police he had strangled his friend and then tried to dismember the body. However, a medical examiner has determined that Campbell's cause of death was an ax wound to the neck.

Prosecutors say Barth's mother and brother discovered Campbell's corpse in his bedroom closet on Christmas Eve, nearly a week after Campbell had gone missing.

Campbell's family sat in the Riverhead courtroom today, gripped by the proceedings. When the prosecutor began to describe the manner of Campbell's death, relatives gasped and broke down in tears. Campbell's family walked quietly out of the courtroom today without speaking to reporters.

Barth faces 25 years to life in prison if convicted. He's being held without bail and is due back in court in two weeks.