LOS ANGELES - One of 4 people shot to death in a suburban Los Angeles real estate office was a 9-year-old boy who apparently died in the arms of his wounded mother as she tried to shield him from gunfire, officials said Thursday.
Authorities also disclosed that the suspected gunman in Wednesday's attack, who was himself wounded before he was taken into custody, knew all of his victims and had a family relationship with at least 1 of them.
The bloodshed inside a 2-story office building in the city of Orange, about 48 kilometers southeast of downtown Los Angeles, marked the third deadly mass shooting in the United States in a month.
But the suspect's connection with those killed appeared to set it apart from the shootings in Georgia on March 16 and Colorado on March 22, in which the victims were believed to have been slain at random.
"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 told a news conference.
The identities of the victims were being withheld pending notification of relatives, police said. The surviving victim, a woman badly wounded while cradling her son in her arms as he was fatally shot, worked at the business, police said.
She remained hospitalized in critical but stable condition on Thursday. Three other adults - 2 women and a man - were killed.
The suspect, identified as Aminadab Gaxiola Gonzalez, 44, a resident of the nearby city of Fullerton, also was listed in critical condition. He may be arraigned on murder charges from his hospital bed on Friday, said Kimberly Edds, a spokeswoman for the Orange County District Attorney's office.
He is accused of opening fire in the office of a mobile home realty company after padlocking entry gates to an interior courtyard of the building, blocking access from the outside.
Police officers, encountering gunfire as they arrived on the scene, were forced to use bolt cutters to open the gates and directly confront the suspect.
"In the meantime, a horrific rampage was going on in offices and people were dying or were being shot," District Attorney Todd Spitzer said.
From outside the office, 2 of the officers engaged in a gunfight with the suspect, who was wounded and arrested, Amat said. Edds said investigators, who recovered a semi-automatic handgun from the scene, had yet to conclude whether the gunshot he suffered was self-inflicted or fired by police.
Authorities said they also recovered a backpack containing pepper spray, handcuffs and ammunition that they believe belonged to the suspect, who had been living out of a motel room in Anaheim before Wednesday.
The suspects in the other March shootings were also arrested. Eight people, 6 of them Asian women, were shot dead at 3 Atlanta-area spas. A gunman killed 10 people at a supermarket in Boulder, Colorado.