A prosecutor on Thursday in the trial of a man charged with killing a pregnant fellow Marine challenged the defense's characterization of the victim as someone who was immature and had a history of lying.

Cesar Laurean, 23, of Las Vegas has pleaded not guilty to first-degree murder in the slaying of Lance Cpl. Maria Lauterbach, 20, of Vandalia, Ohio, in December 2007. Both were stationed at Camp Lejeune and Lauterbach's remains were discovered under his backyard firepit in January 2008.

District Attorney Dewey Hudson challenged Dick McNeil's description of Lauterbach. Besides saying she had a history of theft and lying, McNeil said she was under increased pressure from her mother who wanted her to give up her child for adoption.

"This is a murder case. How is it possibly relevant whether she's stolen things or lied?" Hudson asked after Superior Court Judge W. Osmond Smith III ordered jurors out of the courtroom.

McNeil is trying to portray the slaying as an impulsive act caused by the victim's lies. Still, he challenged prosecutors to prove his client committed the crime.

Prosecution witnesses testified seeing the two together despite Lauterbach accusing Laurean of rape and a protective order requiring they stay apart. McNeil tried poking holes in the picture of two Marines who maintained contact anyway.

Store clerk Pamela Chavis said she saw the two shopping for a Christmas gift at Camp Lejeune's on-base department store days before Lauterbach disappeared. Laurean asked her opinion about crystal that his grandmother might like, so Chavis said she suggested he ask his wife's opinion. An agitated Lauterbach stepped forward and said she was not Laurean's wife, Chavis said.

"I'm positive that was her," Chavis said of the blonde Lauterbach, then about eight months pregnant. She said she saw the two Marines together in the store three of four times.

On cross-examination, Chavis couldn't explain why those details were missing from a report she signed as accurate after an interview by a military investigator.

Laurean, who was born in Guadalajara, Mexico, was arrested in western Mexico in April 2008 after an international manhunt. He was expelled from the Marines after the charges were brought. He faces life in prison if convicted. Prosecutors promised not to seek the death penalty so Mexico would release Laurean to the U.S.

Rashaun Hames, who works at the local bus terminal, said he sold Lauterbach a cross-country ticket to El Paso, Texas, on the day she disappeared. Hames testified Lauterbach told him she was done with the Marines and planned to run away to be with the father of her baby.

"She talked about how things went bad between them and they wasn't supposed to be together," Hames said. "She thought she was going to be with him."

DNA tests showed Laurean was not the father.

Lance Cpl. Blake Costa of Stamford, Conn., testified Laurean told him he had consensual sex with Lauterbach in the spring of 2007 before Laurean's wife and daughter had moved to Jacksonville, home of Camp Lejeune.

That fall, Costa said Laurean asked him to persuade Lauterbach to come to a place where Laurean could seem to casually bump into the now-pregnant Marine. Laurean's military career was in turmoil and he wanted to talk Lauterbach into moving to Mexico where Laurean would send her money while she lived with his relatives.

"I thought it was crazy, but at the time I looked at myself as a friend," Costa said. "We're Marines. That's what we do. We help each other out."

Sgt. Trocon Brumskine said Lauterbach, whom he supervised, was relieved when she was granted a military protective order requiring that she and Laurean stay apart. He even allowed Lauterbach to skip formations if the higher-ranking corporal Laurean would be present.

So it would be a violation for the two to go shopping together, defense attorney Dick McNeil asked. Brumskine agreed. He said he never saw the two together.

McNeil told jurors earlier in his opening statement that Lauterbach had trouble with the truth and she recanted a claim that Laurean impregnated her.

McNeil said prosecutors must prove Laurean killed Lauterbach after she surprised him by coming to his home not long after buying her bus ticket to El Paso, which is on the Mexican border.

"We're not trying at all to minimize her death, but it is vitally important to know all the circumstances," McNeil told jurors in his opening statement. "Life is not generally black and white. There's a lot of gray. And that's what there is in this case."

Hudson told jurors he plans to show DNA evidence of Lauterbach's blood found in Laurean's garage and on a crowbar Laurean gave away to a neighbor. The prosecutor said an autopsy showed that Lauterbach died from a blow to the left side of her head, and that a neck wound caused only minor injury.

Laurean fled hours before Lauterbach's remains were discovered. He left a note for his wife saying he had been arguing with Lauterbach before she pulled out a knife and slit her own throat.