Sex-Change Issue Raised in Murder-Plot Case : Trial: The defense accuses a witness of offering to kill in exchange for funds for an operation. The prosecution says the ex-wife of the targeted man is guilty.

The opening day of the trial of a former Tustin woman accused of plotting the murder of her husband took a twist Thursday when the defense attorney contended that another woman offered to do the killing in exchange for money for a sex-change operation.

Margo J. Thibault-Lemke, 41, went on trial Thursday for allegedly masterminding a plan in late 1987 and early 1988 to kill attorney Richard D. Thibault, then her husband.

But the defense attorney said in opening statements and out of court that Thibault-Lemke actually tried to thwart the murder plans of a woman, who is now a man and one of the prosecution’s main witnesses.

“Margo Thibault didn’t create the (murder) plot and push it along but instead was instrumental in stopping it,” Deputy Public Defender H. Dean Steward said in court.

Prosecutors alleged in a federal indictment that Thibault-Lemke, along with her then-boyfriend, William Lemke, hired four men to kill Richard Thibault. Four different murder attempts failed, prosecutors said. The defendant later married Lemke.

However, Steward said Thursday that David Lamb, one of the men allegedly hired for the slaying, was actually a woman in January, 1988. Lamb wanted to kill Richard Thibault for a slice of the $300,000 in insurance money, the attorney said.

“Her name was Jan Lamb back then and she wanted $10,000 to complete her sex-change operation,” Steward said after the hearing.

He said that Lamb pressed Thibault-Lemke to agree to the murder plan and threatened to kill other members of her family if she didn’t.

Thibault-Lemke was trying to stall Lamb when she was arrested by police, Steward said.

But Assistant U.S. Atty. Paul L. Seave, who is prosecuting the case, said Thibault-Lemke initiated the entire murder scheme and tried to hire Lamb. He said in his opening statements that Lamb was the one who tipped law enforcement authorities to Thibault-Lemke’s alleged murder plans.

He said Lamb was the last of four men contacted for the murder.

Seave could not be reached for comment late Thursday to respond to Steward’s contention that Lamb had been a woman and instigated the crime. Lamb, however, was described in court by Seave as a “strange man.”

Seave said Thibault-Lemke started thinking about killing her husband when they had separated after a four-year marriage. During their separation, she received life insurance offers in the mail that she filled out, signing with her husband’s name, making herself the beneficiary, he added.

The first time she tried to have her husband killed was early in December, 1987, Seave said. She apparently called her brother in Colorado, William McCoy, and asked him to find somebody to commit the murder. McCoy asked his friend Jerry Redman and the two of them agreed to do the killing for $14,000, Seave said.

On their first attempt, McCoy and Redman didn’t even make it out of Colorado because a highway patrol officer stopped their car on a traffic violation and arrested Redman, who had outstanding warrants.

On their second attempt, they were parked outside of Richard Thibault’s home, armed with a handgun and a shotgun, but Redman lost his nerve, Seave said.

Seave said Thibault-Lemke then asked her brother to find another potential killer. Her brother contacted Richard Miller, who broke into Richard Thibault’s house and waited for him in a closet armed with a knife, according to the prosecutor. After waiting for several hours, Miller became bored and left, Seave said.

In a final attempt to kill her husband, Thibault-Lemke hired Lamb to poison him, Seave said. She had originally purchased Lamb’s plane ticket to come out from Colorado and commit the murder but then canceled his ticket when Garden Grove police contacted her on another matter.

When Thibault-Lemke balked, Lamb went to authorities and agreed to telephone her about the murder plans so they could record the conversation, Seave said.

All four men allegedly contacted for the murder have been granted immunity in exchange for their testimony.

Richard Thibault, who took the witness stand briefly Thursday, is expected to testify today when the trial resumes.