SAN ANTONIO -

A man is accused of jumping into an argument between his mother and her ex-boyfriend, then shooting the ex-boyfriend to death.

Shots were reported just after midnight at an apartment complex in the 2300 block of Austin Highway on the Northeast Side.

San Antonio police investigators believe the 44-year-old victim, whom family members identified as Ernest Garcia, went to his ex-girlfriend's apartment to speak with her and the two got into an argument.

The woman told police her son heard her crying in her bedroom and asked her if her ex-boyfriend had hit her.

Police said the woman didn't respond and her son pulled out a handgun, and told her ex-boyfriend to leave.

Officers said the ex-boyfriend refused to leave and the son, identified as Jonathan Jose Guillen, 23, shot him in the torso.

Guillen (pictured) fled with his infant son. Police have not said if they believe the child is in any danger.

Garcia's mother said her son didn't want to go to the apartment, but his ex-girlfriend talked him into it.

"She kept calling him on the cell phone. She kept calling him. He was going to go to bed, because he knew that he was going to help me this morning," McDougald said.

Overnight, Garcia's mother couldn't get in touch with her son, and knew something was wrong.

"I felt it. I got up, and I didn't know anything," she said.

Garcia's mother said her son had recently been released from prison on parole, and was trying to change his life, but that his recent girlfriend wasn't the change he needed.

"My son had bad choices with women. Bad choices. I told him, as a matter of fact, two days ago, I told my son Ernest, I said, 'Ernest, leave this woman alone,'" she said.

San Antonio police said an investigation is ongoing, but Guillen will likely be charged with murder.

Detectives, meanwhile, are searching for Guillen, who is described as being 5 feet 8 inches tall, weighing 185 pounds, with black hair and brown eyes.

Anyone with information regarding Guillen's whereabouts is urged to call Crime Stoppers at 224-STOP.

Police say he may be armed but they do not believe his 11-month-old son is in any danger.

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