By CBSLA Staff

ORANGE (CBSLA) – A little boy died in his mother’s arms as she was trying to save him during a horrific shooting at an office building in Orange that left four people dead Wednesday.

The boy’s mother, according to family members, survived the mass shooting but is in critical condition at the hospital. She is on life support after being shot in the head twice.

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As police ran towards the gunfire, they discovered the child was one of four victims shot to death by a man identified as Aminadab Gonzalez, 44, of Orange County.

At a news conference, police said Gonzalez locked the victims, who he knew through personal or business relationships, in the complex.

“It appears the suspect used a bicycle-type cable lock to secure the gates from the inside on both the north and the south sides of the courtyard,” said Lt. Jennifer Amat of the Orange Police Department.

Police say they fired through the locked gates as they rushed to the crime scene at Unified Homes, a family-run real estate business, on West Lincoln Avenue in Orange Wednesday night.

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The suspect was taken to the hospital with at least one gunshot wound.

“Officers had to engage the suspect from outside the premises until bolt cutters could be brought to the scene in order for them to gain entry to the premises,” said Orange County District Attorney Todd Spitzer. “In the meantime, a horrific rampage was going on and people were dying and being shot.”

The shooter, according to sources, had a stockpile of ammunition.

“Investigators have recovered several items at the scene including a semi-automatic handgun and a backpack containing pepper spray, handcuffs, and ammunition which we believe belonged to the suspect,” Spitzer said.

Police found 3 deceased victims, a man and a woman, at the business, and another woman outside on a staircase landing.

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Alec Torres, a partner at Unifed Homes, was not in the office when the attack happened but added that the wife of the alleged shooter worked at the business years ago before quitting. Torres said she tried to rejoin the company two years ago but her job was filled.