Police identified the suspect and possible motive in the Orange, California, shooting that killed 4 people

• Police identified the suspect in a Wednesday shooting that killed four people in Orange, California.
• The suspect was identified as Aminadab Gaxiola Gonzalez, 44, from Fullerton.
• The police said he knew all the victims on a business or personal level.

The suspect in a shooting that killed four people, including a child, at a business in Orange, California, on Wednesday was identified as Aminadab Gaxiola Gonzalez, 44, from Fullerton, California, authorities said on Thursday.

Lt. Jennifer Amat of the Orange Police Department said at a press conference that Gonzalez knew all the victims on a personal or business level and that the motive was believed to be related to those relationships.

"This appears to be an isolated incident, and we believe everyone knew each other," she said.

A 9-year-old boy, a man, and two women were killed in the shooting, though their identities have not been made public. A fifth person was critically injured and taken to a hospital, authorities said.

The suspect was also transported to a hospital with a gunshot wound, authorities said.

Amat said on Thursday that the shooting happened at a business called Unified Homes.

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The police said that the entrances to the building had been shut with bike locks, blocking officers from getting in during the shooting, and that investigators found a semi-automatic handgun, handcuffs, and ammunition at the scene.

In a Facebook post about the shooting on Wednesday night, the Orange Police Department said that shots were fired when officers arrived and that an "officer involved shooting occurred."