The Los Angeles County Sheriff has confirmed that the 45-caliber handgun used in the murders of two students and the wounding of three others at Saugus High School had been assembled from a kit, the purchase of which would likely bypass California law that requires a background check before the purchase of a complete factory-made weapon.
Alex Villanueva said in a Twitter post Thursday that the gun had been home built, and detectives were now examining the teenage killer's computer and digital records to try to find out if the 16-year-old had purchased or assembled it himself.
Unfinished or kit guns will not function until the purchaser completes additional drilling, milling or other craft work, instructions for which are easily available online.
NBC4 reported last Friday that the handgun found at the shooting scene immediately appeared to investigators to have had parts exchanged or modified. The gun's receiver did not bear a serial number, law enforcement sources said.
Unfinished receiver components are legally considered guns, even absent any other parts. Recent California law requires kit guns to be registered with the state once they have been completed and turned into a functioning firearm.
Commercially-made guns sold in stores are stamped with a manufacturer's name and a serial number on each receiver.
The Bureau of Alcohol Tobacco Firearms and Explosives has been assisting the Sheriff's Department with tracing the origin of the murder gun and several other firearms and firearm parts found during a search of the teenage killer's home.
Over the summer, ATF Los Angeles Special Agent in Charge Carlos Canino told I-Team reporter Lolita Lopez that an increasing number of homemade or assembled guns, sometimes called "ghost guns," were appearing at crime scenes.
"These firearms are extremely dangerous," Canino explained, as anyone can buy the parts without a background check and there's little ability to trace the ownership. He showed NBC4 a number of handguns and rifles seized during a gang investigation in Santa Ana and said some of them were built from parts ordered on the internet.
"At least one of these guns, that I know of, was used in a robbery which resulted in a shooting," he said.
In August, a rifle assembled from unregulated parts was used to murder CHP Officer Andre Moye, who was shot during a traffic stop in Riverside. The killer was a convicted felon and would have been unable to legally purchase any firearms.
California Gov. Gavin Newsom recently signed a bill into law that will require incomplete firearm receivers to only be sold through licensed dealers with the same background check required for conventional firearm sales. The law doesn't take effect until 2024.
The discovery of any guns in the Saugus High School shooter's home was particularly troubling for detectives, the sources told NBC4, because Sheriff's deputies had seized and destroyed a number of guns several years ago that had once belonged to the teen's father. The guns were seized as the result of a mental health inquiry, and that event would have precluded the father from buying any additional guns. The father died in late 2017, and his son was too young to purchase any firearms or ammunition himself.