A 9-year-old boy, who died in the arms of his wounded mother who desperately tried to save him, was among the victims of a fatal Los Angeles shooting that killed four individuals on Wednesday.

“It appears that a little boy died in his mother’s arms as she was trying to save him during this horrific massacre,” Orange County District Attorney Todd Spitzer said during a news conference.

Brutal Shooting Attack

The shooting incident occurred in Orange, California, about 30 miles southeast of central Los Angeles. It was recorded as the third most deadly mass shooting in the United States in the last month.

There were two other similar incidents in March, one where a suspect killed eight people, six of which were Asian women at three separate Atlanta-area spas, while the other is where a man fired gunshots at a Boulder supermarket, killing ten people.

However, California investigators said that, unlike the first two incidents, the most recent suspect knew the victims. They said he had a motive and ruled out the possibility of a random act of violence.

“The preliminary motive is believed to be related to a business and personal relationship which existed between the suspect and all of the victims,” Orange Police Department Lieutenant Jennifer Amat said during a news conference.

Authorities identified the suspect as 44-year-old Fullerton resident Aminadab Gaxiola Gonzalez. The four victims included the young boy, one man, and two women. Both the shooter and the woman who protected the child were in the hospital in critical but stable conditions, said Amat.

Police said the suspect entered the Unified Homes’ office complex on Wednesday afternoon. He then locked the gates behind him using bicycle locks. When officers arrived, the shooter was still firing his gun. They were unable to quickly reach the scene due to the chains on the gates.

“In the meantime, the horrific rampage was going on in offices and people were dying or were being shot,” said Spitzer. Two officers engaged in a shootout with the suspect from outside the courtyard. Police were able to wound the suspect and later took him into custody, Inquirer reported.

Officials recovered a semi-automatic handgun from the suspect and took his backpack which contained pepper spray, handcuffs, and ammunition. Police searched inside the complex to find a dead woman on an outdoor landing upstairs, a dead man inside an office building, a another dead woman in a separate office building, said Amat.