TRENTON, N.J. -- Defense lawyers asked a judge Monday to throw out the charges against former NBA star Jayson Williams, who is accused of shooting a limo driver to death and trying to cover up his role.

The defense accused prosecutors of misconduct before the grand jury that indicted Williams on first-degree manslaughter and other charges.

Defense lawyers also asked the judge to separate manslaughter and aggravated assault charges from those related to the alleged cover-up.

Steven C. Lember, acting Hunterdon County Prosecutor, denied the defense's accusations and said the requests were expected.

Prosecutors were asked to file their responses by the end of October. The judge hopes to rule by mid-December.

The defense accused the prosecution of violating state and national standards, as well as the U.S. Constitution, by repeatedly telling grand jurors that Williams exercised his right to remain silent.

Exercising that right cannot be held against a defendant and would be inadmissible during trial, the defense said.

The defense also said the grand jury received insufficient instructions and the prosecutor only presented a partial picture of the shooting, leaving out details that cast Williams in a positive light.

The driver, Costas Christofi, was invited inside Williams' mansion early Feb. 14 after picking up the former NBA All-Star's friends at a Harlem Globetrotters game.

Prosecutors say Williams was recklessly handling a 12-gauge shotgun when it fired, hitting Christofi in the chest.

Prosecutors say Williams and two other men tried to hide the clothes, replace Williams' fingerprints on the shotgun with the victim's and persuade other guests to say Christofi had been upstairs alone.

The other two men -- Kent Culuko and John Gordnick -- have pleaded guilty to tampering charges and agreed to testify against Williams.

The 6-foot-10 Williams was among the NBA's best rebounders when leg injuries ended his career. He retired from the New Jersey Nets in 2000.

After the shooting, Williams was suspended from his job as an NBA analyst for NBC.