Williams is scheduled to appear in court in Somerville. He's expected to get 18 months in prison after pleading guilty last month to aggravated assault in the February 2002 death of hired driver Costas Christofi.
Williams was acquitted of aggravated manslaughter in 2004 but convicted on four counts of covering up the shooting. His sentence for those convictions will run concurrent to the assault sentence.
When he pleaded guilty, Williams had faced a retrial on a reckless manslaughter count.
Witnesses testified Williams snapped a shotgun shut in the bedroom of his New Jersey mansion after a night of drinking. The gun went off, hitting Christofi in the chest.