A Franklin County jury can hear about four contacts police had with Gregorio Luna Luna on domestic violence allegations in the years before his ex-girlfriend was killed, a judge ruled Monday.

Judge Robert Swisher gave prosecutors clearance to use the evidence in Luna Luna's upcoming murder trial.

The 32-year-old man is accused of fatally stabbing his young son's mother on May 24, 2010.

The trial starts Monday with jury selection.

Luna Luna is charged in Franklin County Superior Court with aggravated first-degree murder. The charge includes the aggravating circumstances that there was a no-contact order in place against Luna Luna at the time of the slaying and that there was a pattern of domestic violence in the relationship.

Griselda Ocampo Meza, 21, died in her Pasco apartment before she could get to a hospital. The couple's 5-year-old son was rushed out of the home by Ocampo Meza's new boyfriend before she was stabbed.

Luna Luna's lawyers have said they will be arguing self-defense.

That opened the door for special prosecutors Andy Miller and Anita Petra to delve into Ocampo Meza's medical history and reports of prior abuse by Luna Luna.

On Monday, Swisher heard brief testimony from four Pasco police officers and one Kennewick officer about contact they'd had with Luna Luna. All of the officers speak Spanish and said that is the language they spoke with him.

Pasco Officer Saul Mendoza said that on Sept. 4, 2008, he responded to an 801 N. 22nd Ave. apartment for an assault. Mendoza said he was instructed to talk to Luna Luna about his involvement, while Officer Mario Becho spoke to Ocampo Meza.

Mendoza identified Luna Luna -- seated in court in an orange jail uniform -- as the man he initially requested identification from before talking.

"What I recall was asking him if he had had any kind of argument with the female, what his involvement was," Mendoza testified. "... He said, 'No.'"

Becho told the court that Ocampo Meza informed him she had been in an argument with her boyfriend and he had assaulted her. The officer said he then wanted to confirm with Luna Luna "whether he had done it," but first talked to Mendoza to find out what they had discussed.

When Becho approached Luna Luna, he had probable cause to suspect he had done the assault, but Luna Luna had not been read his Miranda rights yet.

Miller conceded that any statements Luna Luna made after that point are not admissible. Miller, the Benton County prosecutor, is handling the case because of a conflict with the Franklin County Prosecutor's Office.

Swisher agreed that evidence from Becho's conversation cannot be used at trial.

On Dec. 31, 2009, Officer Ismael Cano responded to the same complex where Ocampo Meza informed him she'd been assaulted by her husband. The two were talking when she received a call from Luna Luna and handed the phone to the officer.

"I was a brief conversation. I told him I needed to speak with him and asked if I could meet with him. He told me he was at Albertsons nearby," Cano said. "I told him did he want me to come over or he'd come back to the apartment, and he said he'd come back to the apartment. Then he hung up the line."

Luna Luna denied an assault when talking to the officer in person, but claimed that he had found out about his wife having an intimate relationship with his brother, Cano said.

Luna Luna and Ocampo Meza were not married, but had been together for seven years when she ended their relationship in January 2010. They had a son together, who was 5 at the time of his mother's death.

Officer Jonathan Davis said he went to Ocampo Meza's apartment on Jan. 30, 2010, for an alleged assault. Officers spent several hours looking for Luna Luna before making a traffic stop on his vehicle on North Ninth Avenue in Pasco.

Davis read Luna Luna his Miranda rights in Spanish. Luna Luna didn't invoke his right to an attorney and agreed to speak with police, though details of that conversation were not testified to in court.

Luna Luna was arrested on suspicion of domestic violence and malicious harassment for that incident, and ultimately handed over to U.S. Immigration and Customs Enforcement. He was sent back to Mexico on May 1, 2010, but recrossed the border sometime in the next 22 days and stole a Snohomish friend's car on May 23 to drive to the Tri-Cities.

Kennewick Cpl. Matt Newton said he went to Roberto's Tacos on May 23, 2010, to help translate for an order violation report.

Ocampo Meza explained that she had been eating food at the Kennewick restaurant with her boyfriend and son when her ex, Luna Luna, approached them. They had a brief conversation and Ocampo Meza told him to leave because of the protection order between them, Newton said.

Ocampo Meza also told police that since Luna Luna had left the restaurant, he had called her cell phone two more times. She gave that number to Newton, who dialed it and asked to speak to Luna Luna, but the call was disconnected once he identified himself as the police.

Ocampo Meza was killed just hours later.

If Luna Luna is convicted at trial, he will spend the rest of his life in prison.