PASCO — Jurors in the Pasco murder trial of Gregorio Luna Luna were asked Thursday to step into his mind and his heart and understand that he was a man who only wanted the best for his young son.

Luna Luna had hopes and dreams of building a family with the woman he loved, his lawyer said, but Griselda Ocampo Meza ended the volatile relationship in January 2010.

So early one morning, after not seeing his son for four months, Luna Luna pushed his way into his former Pasco apartment to get his 5-year-old son and take him back to Mexico, Karla Kane told the jury in her opening statement.

His sole purpose was to raise the boy in the culture he knew, but Luna Luna also hoped Ocampo Meza would join him in their native country and rebuild their relationship.

Instead, the 21-year-old mother was killed in what prosecutors describe as a planned attack by a man who felt if he couldn't have Ocampo Meza, then no one else should.

Luna Luna -- on trial in Franklin County Superior Court for aggravated first-degree murder -- explained to a friend on May 23, 2010, that he was going to kill his ex-girlfriend the next morning, special prosecutor Andy Miller said.

He would not listen to his friend's attempts to talk him out of it, saying that his son Allen "would be better off living with someone else than living with that slut," Miller said. Miller then apologized to the jury for repeating the vulgar slang Luna Luna reportedly used in that reference to Ocampo Meza.

The trial opened Thursday after three days of jury selection.

Luna Luna, 32, was expected to argue self-defense in the May 24, 2010, fatal stabbing; however, his lawyers announced Wednesday that they were withdrawing that argument.

Miller is the Benton County prosecutor. He and Deputy Prosecutor Anita Petra have the case because of a conflict with the Franklin County Prosecutor's Office.

In his opening statement, Miller said the jury will hear evidence about "the assaults and harassment that the defendant had inflicted on Griselda, the mother of their child."

The charge is aggravated because the couple reportedly had a history of domestic violence, and there were two separate court orders for Luna Luna to stay away from the victim at the time of the slaying.

If Luna Luna is convicted as charged, he will spend life behind bars without the possibility of release.

After seven years of dating, Ocampo Meza ended the relationship in January 2010, and Luna Luna moved out of their North 22nd Avenue apartment. He was arrested later that month for an assault and eventually sent to the Northwest Detention Center in Tacoma while awaiting deportation proceedings.

Luna Luna was returned to Mexico on May 1, 2010, but crossed back over the border and returned to the Northwest during the next three weeks.

He was living with a couple in Snohomish when he stole the friend's car, only to call later that day to apologize while also sharing his alleged plans to kill Ocampo Meza, Miller said. Later that night in the Tri-Cities, Luna Luna confronted Ocampo Meza at a Kennewick restaurant and threatened her and her new boyfriend.

Jairo Flores-Flores said while Ocampo Meza asked an employee at Roberto's Tacos to call 911, he followed Luna Luna into the restaurant's parking lot. Luna Luna then said "that we were going to see each other later, that he was going to kill Griselda."

Flores-Flores, in emotional testimony Thursday, said he went home but got a call from his girlfriend at 9 p.m. saying she was scared. She asked him to stay with her.

Despite being warned of what her ex-boyfriend might do, Ocampo Meza and Flores-Flores were surprised at 4 a.m. the next day when Luna Luna barged into the two-story apartment after allegedly taking a key from the roommates who were leaving for work.

"He came in and he started to beat up Griselda. He had a knife in his hand," Flores-Flores told the jury. "He was beating on her and pulling on her hair, and he was telling her that now he was going to kill her. She was yelling for me to take the little boy out."

Ocampo Meza took "desperate steps" to stop her ex, Miller explained. But when she realized their son was awake and downstairs seeing the fight -- based on his shouts of, "Mi mama, mi mama" -- she pleaded with her boyfriend to at least save the boy by getting him out of the apartment, he said.

Flores-Flores, in his testimony, said Allen also was yelling to get him out of there "because he was afraid of him." As he picked up Allen and ran out of the house, Flores-Flores looked back and saw Luna Luna swinging a knife and now kicking Ocampo Meza in the face.

The boyfriend was pounding on a neighbor's door to get Allen to safety when he said Luna Luna attacked him and demanded that he hand over the boy.

"He grabbed me and he told me not to do anything crazy, and to leave him alone," Flores-Flores said. He said he fought back by hitting Luna Luna at least once and drawing blood.

Luna Luna left the complex by jumping over a fence and getting into a nearby car.

Flores-Flores then ran back into his girlfriend's apartment and found her face down in the kitchen with a pool of blood below her chest. A bent knife and a broken knife were nearby. He said he did not know what to do, but police soon arrived at the apartment.

Ocampo Meza died from a stab wound to her chest.

Luna Luna was arrested hours later, hiding in the bathroom of an abandoned home. He reportedly did not realize Ocampo Meza was dead until police later showed him pictures.

Kane asked the jury while listening to evidence to "step inside the mind of Gregorio, to feel what he was feeling, to think what he was thinking."

The couple's story began in Mexico where the two met. Ocampo Meza eventually moved in with her boyfriend's family in the small town of Puebla. Their relationship thrived through love and the support of their family, and soon they welcomed Allen, Kane said.

Luna Luna "wanted a better life for his child than what he was providing him," so he decided to move to Washington for work, Kane said. He planned to go back to Mexico once he saved up some money, but Ocampo Meza reportedly insisted on joining him, the lawyer said.

"All his dreams were torn away from him on Dec. 31, 2009," when Luna Luna allegedly discovered love letters between Ocampo Meza and his brother, Erik.

"His life drained out of him. His visions, his hopes, his dreams for his family were gone," Kane said. "Not only was that dream gone for him, but he was also betrayed by his own blood."

Twice he tried to take his son "to return to his roots," but he reconciled with Ocampo Meza in California while on the way the first time. Luna Luna was arrested on the second attempt.

Luna Luna wanted Ocampo Meza to follow him to Mexico so she could talk to her parents about their relationship and they could "help her to see the light, see she had a man that loved her. He wanted nothing more than to see his son raised with family," Kane said.

On that morning in May 2010, "he went to that apartment with one sole purpose, to get his son to return him to the culture that he knew -- to return to Mexico," she said, adding Luna Luna did not act with premeditation when he confronted Ocampo Meza.

Maria Manzanares testified that she befriended Ocampo Meza at a meeting about domestic violence, held in their apartment complex's office. She said she was with Ocampo Meza after one of Luna Luna's attempts to take his son, when he called her sad and angry, and said he didn't care if she tried to throw him in jail.

Manzanares said that the night before her friend was killed, an upset Luna Luna came to her apartment and wanted to know if his ex-girlfriend was living with someone. This was after the confrontation at Roberto's Tacos, and Manzanares said he asked for her phone number so he could keep in touch because he really wanted to see his child.

She awoke the next morning for work and knew something had happened to Ocampo Meza when she looked out the window and saw police and yellow tape around her friend's open front door.

Manzanares said she then called Luna Luna. He answered, then hung up on her.

She gave the number to the officers outside, but added that Luna Luna later called her and only identified himself before again hanging up.

The trial continues today at the Franklin County Courthouse, but it will end for the day by noon. It is expected to last up to three weeks.