A 32-year-old man on trial for the death of his young son's mother won't be telling jurors that he was defending himself when she was stabbed.

Gregorio Luna Luna is withdrawing his self-defense argument, his lawyer told the court Wednesday.

Defense attorneys on the Franklin County Superior Court case announced last month that Luna Luna was claiming he acted in self-defense when Griselda Ocampo Meza was killed inside her Pasco apartment early May 24, 2010.

But just minutes after a jury of seven men and seven women was seated Wednesday morning, Karla Kane said they were changing their defense strategy though she did not reveal what it is.

Kane told Judge Robert Swisher of the change when the jury, which includes two alternates, was not in the courtroom.

Special Prosecutor Andy Miller told the judge that if the defense wanted to stipulate that Luna Luna stabbed Ocampo Meza with premeditated intent, the state might have a different view of what evidence is introduced at the trial -- specifically dealing with the couple's history of domestic violence and a protection order that was in place against Luna Luna at the time of the slaying.

Kane said the defense wouldn't admit that because then there would be no need for a trial.

"Our client does in fact deny that allegation and that's why we're here in trial, to make the state prove it," she said.

Luna Luna is charged with aggravated first-degree murder. He will spend the rest of his life in prison if convicted of the charge along with two aggravating factors.

His trial started Monday with jury selection. Opening statements are this morning, with the trial expected to last up to three weeks.

Luna Luna and the victim had been in a seven-year relationship when Ocampo Meza ended it in January 2010. The following month, she filed her first of two requests for a protection order after a series of alleged assaults by Luna Luna.

Ocampo Meza, in her petition, said Luna Luna had threatened to make her life miserable and that she was afraid he would kill her after two previous attempts. She was granted a two-year order, which told Luna Luna to stay away from his ex-girlfriend and their 5-year-old son and to not commit any "acts of abuse."

Luna Luna was sitting in the Northwest Detention Center in Tacoma awaiting a deportation hearing when he wrote letters to Ocampo Meza saying he "was going to finish the job," court documents said.

He was returned to his native Mexico on May 1, 2010. The details of what Luna Luna did over the next 22 days are not known, but he was back in Washington state by May 23, 2010, when he stole a car from a friend in Snohomish and drove to the Tri-Cities.

Luna Luna reportedly confronted Ocampo Meza, 21, at a Kennewick restaurant on May 23. She was with her new boyfriend and son, and called police after reminding Luna Luna that he was violating the protection order.

Ocampo Meza had changed the locks on her apartment just weeks before. But early May 24, Luna Luna forced her roommates to give him a new key as they left for work before 4 a.m., according to prosecutors.

Luna Luna then got into the North 22nd Avenue apartment and started fighting with his ex. Her son was rushed out of the home by her boyfriend before Luna Luna allegedly stabbed her once in the chest with a kitchen knife.

Ocampo Meza died before she could get to the hospital.

The suspect was arrested 11 hours later at a vacant east Pasco home. Luna Luna has been in custody in the Franklin County jail in lieu of $5 million bail.