Santa Clarita / Antelope Valley : Ex-Girlfriend Says Martial Artist Told Unknown Slaying Details : Trial: Cheryl Desmarteau also says the suspect changed his alibi. The defense gets a witness to say he was unsure about seeing the accused near the crime scene.

The ex-girlfriend of a martial arts instructor accused of killing a co-worker testified Thursday that the defendant knew details of the incident before police and changed his alibi during the weeks after the slaying.

Deputy Dist. Atty. Robert Foltz also continued to build his case against Stuart Edward Milburn, 27, by presenting two witnesses to the Los Angeles Superior Court jury who said they saw Milburn near the murder scene at about the time it occurred.

But Milburn’s attorney, Darryl Mounger, got one witness to admit he has doubts that Milburn is the person he saw the night of the murder. Mounger also pointed out that the other witness may be confused about what day she claims to have seen Milburn.

Milburn is accused of killing Veronica Estrada, 29, about 8:15 p.m. Dec. 15, 1993, as she walked home alone on Soledad Canyon Road in Santa Clarita. He is one of the people who found her partly clothed body in bushes alongside the road the next morning.

Prosecutors have charged that Milburn killed Estrada because he was jealous of her accomplishments. She was the American Taekwondo Assn.’s top-ranked female competitor in the second-level black belt division and was named instructor of the year at Taekwondo USA in Canyon Country where she and Milburn worked.

Cheryl Desmarteau, a San Fernando Valley resident, testified that she met Milburn in April, 1993, and that they later dated until the end of the year. She said he asked her to come to his house the night of the day Estrada’s body was found, and told her Estrada had been “struck from behind and strangled” between 8 and 9 p.m. the night before.

Sgt. John Laurie, a Los Angeles County Sheriff’s Department homicide detective, testified that he interviewed Milburn briefly several hours after Estrada’s body was found, but never told Milburn those details because they were still unknown to police officials.

Prosecutor Foltz said nor did other investigators tell Milburn about the time and cause of death.

Milburn told her he had left the studio about 8 p.m. the night of the murder, Desmarteau said. “He said he was not feeling well, he left the studio and went home to sleep,” she said.

However, when Milburn found out in January that he was a suspect, Desmarteau said that he then told her he had been at a record store next door to the tae kwon do studio where he worked. That statement remains Milburn’s alibi at the trial.

Mounger said Milburn’s statement about going home the night of the murder was intentionally misleading, but for relatively innocent reasons. “He talked to some other female (that night),” he said. “He just didn’t want to tell her that.”

Also on Thursday, two motorists testified that they were driving along Soledad Canyon Road near the murder scene and saw a man on foot between 8:15 and 8:30 p.m. Both witnesses later picked Milburn as that man when police showed them a photo lineup of six suspects.

Frank Alfonso, a Canyon Country resident, said he saw a man step up on a curb between 8:25 and 8:30 p.m. But he told Mounger the man he saw wore different glasses from those Milburn wears now and that the man had disheveled blond hair. Milburn’s is red.

“As you look at Mr. Milburn today, can you say for sure he is the person you saw that night?” Mounger asked.

“No I cannot,” Alfonso replied.

But Alfonso also testified that he is positive Estrada’s boyfriend, Eddie Hockaday, is not the man he saw.

Mounger filed a motion Monday stating he will present evidence Hockaday or an unknown assailant committed the murder. Judge Charles E. Horan is expected to rule after prosecutors file a written response.

Foltz has dismissed Mounger’s motion as “a joke” intended to divert attention from Milburn.

Milburn is in custody without bail. He faces life in prison without the possibility of parole if convicted of first-degree murder with special circumstances of lying in wait, forcible sodomy and attempted rape.