A Napa judge on Wednesday let stand the grand jury indictment of a Napa dentist accused of murdering his estranged wife almost 10 years ago.

Napa County Superior Court Judge Stephen Kroyer agreed that prosecutors made mistakes during the grand jury proceeding of Michael Posey, 58, but said, "It did not rise to the level to where it denied him due process of the law."

Last year, the Napa County criminal grand jury indicted Posey for the murder of Elizabeth Posey, 27, on April 19, 1996, at the doctor's home in northeast Napa.

On Wednesday, Posey's attorney Colin Cooper of Berkeley called the grand jury procedure "the most unfair aspect of the justice system. It's all done in secret. It's one-sided evidence. This case is almost 10 years old and there has been no new physical or forensic evidence presented."

Grand jury proceedings are not held in open court and defense counsel is not allowed to be present. Prosecutors, in addition to presenting their case, are required by law to tell grand jurors about evidence that might favor the defendant.

After hearing the evidence, the jurors determine if there is probable cause to hold a defendant over for trial.

Cooper charged that when all of the evidence had been presented, the prosecution erroneously instructed the grand jury members that they could not request additional evidence or call more witnesses. He said prosecutors failed to present testimony that could have exonerated Posey and failed to limit the testimony of a witness to his field of expertise.

The scene

On the night Elizabeth Posey died, she had brought the couples' children, 1 and 3, to visit their father in his Napa home. She was living in Cordelia while she and Dr. Posey were going through a strained divorce.

Dr. Posey told officers that his wife became angry when he refused to pay for her breast implant surgery. He said she went to the bedroom and retrieved a Walther PPK .380-caliber semi-automatic handgun, returned to the kitchen and fired a shot at him. Posey said the bullet missed him and lodged into the kitchen cupboard.

A struggle for the handgun ensued and it went off, he said. Posey called police and when they arrived they found Elizabeth dead on the kitchen floor from a single gunshot wound to her head. Dr. Posey was interviewed by investigators that night and released.

More than nine years later, on May 27, 2005, he was arrested in front of his office at Seminary and First streets.

Challenging experts

On Wednesday, Cooper argued Dr. Vincent DiMaio, chief medical examiner in Texas, testified to evidence at the grand jury hearing that was not in his field of expertise.

"Dr. DiMaio is supposed to be an objective criminalist, (but) his testimony is biased. He injected his own personal opinions, such as Dr. Posey had strong hands because he is a dentist, and that Elizabeth would not have been able to control the gun because she had painful breasts due to her recent implants," Cooper said.

"He said Dr. Posey was a liar."

Napa County Deputy District Attorney Rob Wade rebutted Cooper's arguments.

"The grand jury is not an unfair process. The proceeding lasted four days. We called 17 witnesses and played four hours of the defendant's statement he gave the police for the grand jury members," Wade said.

Wade argued there was strong forensic evidence, such as scratches on Posey's back and fibers from his shirt under his wife's right thumb nail. Wade argued that that evidence showed Elizabeth Posey could not have been holding the gun with both hands during the struggle, as Dr. Posey said.

During the grand jury hearing, testimony was presented to show the gun jammed after it was fired.

"If that happened when the bullet was fired into the cupboard, they would have been fighting over a piece of metal, not a loaded firearm," Wade said. "There is strong forensic evidence to uphold the grand jury indictment."

Cooper responded. "If the evidence is so conclusive, why did it take so long (to file charges against Posey)," Cooper asked. "I'll tell you why, because they had to find a forensic criminalist who was biased."

Judge Kroyer said the criticism of the grand jury hearing was serious. He said the most troubling aspect was DiMaio's remarks about Posey.

"He should not have been allowed to say those things. One witness cannot call another witness a liar," Kroyer said. Kroyer said, however, the lay person hearing such testimony would dismiss it.

Posey's trial is set for May 30. He is out on bail after posting a $6 million property bond.