What to Know Law enforcement sources say deputies from the Santa Clarita Sheriff’s station detained the teenager’s father in the past.

Guns were seized from the home as a result.

How the teen got ahold of the .45 caliber pistol used in the school shooting wasn't yet known.

As detectives searched the home of a 16-year-old boy who allegedly walked onto campus Thursday morning and opened fire on his classmates, leaving two of them dead and injuring others, authorities revealed they discovered other guns at the teen's home.

Detectives, with the help of SWAT teams and bomb squads, served a search warrant Thursday at the home of Nathaniel Tennosuke Berhow, close to Saugus High School where the shooting took place.

"The police went into the house. They swarmed the house," the suspect's neighbor Tom Morreale said.

According to court records, the 16-year-old's mother and father took a dispute to court in 2016 over who should have custody of the teen.

That case was resolved in August 2016.

Around the same time, several law enforcement sources have told NBC4 that deputies from the Santa Clarita Sheriff’s station detained the teenager’s father on an involuntary hold for a mental health evaluation.

As a result of that, deputies seized a number of firearms from the home. Those guns were eventually destroyed by the county.

After that event, sources say the father would have been considered a prohibited purchaser, or someone who could not legally purchase a gun in California.

The father died of natural causes in December 2017.

How the teen got ahold of the .45 caliber pistol used in the school shooting wasn't yet known. Agents from the Bureau of Alcohol Tobacco and Firearms have been on scene throughout the day working to trace its history from manufacture to the crime scene.

The question remains over how the weapons in the home were obtained, considering some guns in the home were already confiscated in years past, and the teen gunman was too young to purchase them on his own.

"His father died very recently. So apparently he had a lot of stress from that," Morreale said.

Another neighbor said he was shocked and never would've expected the teen to shoot anyone.

"He always had a smile on his face," Jacob Labrie said.

John Cádiz Klemack contributed to this report.

School Shooting Incidents Since 2013

Everytown.org defines the incidents mapped below as any time a firearm discharges a live round inside or into a school building or on or onto a school campus or grounds, as documented by the press and, when necessary, confirmed through further inquiries with law enforcement or school officials. Incidents in which guns were brought into schools but not discharged are not included.

Source: Everytown.org, NBC Staff Reports

Last updated on Nov. 14, 2019

Read full coverage on the shooting here.