D.A. Seeks to Amend Charges Against Gionis : Trial: Counts would leave prosecutors with less to prove in court. Gionis is accused of masterminding the assault on ex-wife Aissa Wayne.

In an apparent attempt to make it easier to win a conviction, prosecutors Thursday sought to amend the charges against Dr. Thomas A. Gionis, who is accused of masterminding the assault on his ex-wife--the daughter of John Wayne--and her then-boyfriend two years ago.

“Obviously, the prosecutor wouldn’t be doing this if he didn’t think it would help him get a conviction,” said William J. Kopeny, one of Gionis’ attorneys.

Gionis’ first trial in December ended in a mistrial when the jury deadlocked 9 to 3 in favor of a conviction.

Prosecutors want to streamline the case against Gionis, 47, an orthopedic surgeon from Pomona, who is accused of ordering the Oct. 3, 1988, attack on Aissa Wayne and her then-boyfriend, Roger W. Luby, in the garage of Luby’s Newport Beach estate. Luby’s right Achilles’ tendon was cut and he was beaten with a gun. Wayne’s face was smashed into the concrete floor several times.

Prosecutors would like to change the charge of conspiracy to commit assault with a deadly weapon, to simply conspiracy to commit assault. They also want to add a new charge of conspiracy to commit residential trespass. The remaining charges against Gionis would be two counts of assault.

The district attorney’s office would drop four of its original charges: two counts of false imprisonment, one count of residential burglary and one count of intimidation of a witness.

The new charges are broader and would essentially leave prosecutors with less to prove in court. However, before prosecutors can amend the charges, their proposal must be approved by Superior Court Judge Theodore E. Millard, who is presiding over the case.

The next hearing before Millard is scheduled Feb. 21. At that time, Gionis’ lawyers may oppose the prosecution’s attempt to amend the charges.

Deputy Dist. Atty. Christopher J. Evans declined to comment about the proposed amendment. However, one law enforcement official involved in the case said it is not at all uncommon to revise charges after learning what jurors at a first trial thought of the case.

If the judge permits prosecutors to amend the charges, it could mean a new round of pretrial hearings before Gionis faces a second trial.

Prosecutors claim that Gionis, who was engaged in a bitter child-custody fight with Wayne, hired two gunmen through his private investigator, O. Dan Gal. The purpose, prosecutors contend, was to intimidate Wayne in her testimony at an upcoming custody hearing.

Several jurors at the first Gionis trial said they were troubled by the conspiracy charge because they did not know if it meant the doctor had to know in advance that the men sent to assault the couple would be taking guns.

The jury foreman told prosecutors that if the conspiracy charge had not included the “deadly weapon” issue, Gionis would probably have been convicted.

Despite the fact that prosecutors want to reduce the Gionis case from seven felony charges to four, the doctor would still face the same maximum possible sentence if convicted: eight years.

Jerrel Hintergardt, who admitted he led the attack on Wayne and Luby, is already serving an eight-year prison sentence after his conviction in the attack at a separate trial.

Gal and the other gunman, Jeffrey K. Bouey, have also admitted their roles. They are awaiting trial. Bouey is expected to be permitted to plea bargain in exchange for his testimony against Gionis and Hintergardt.