LOS ANGELES _ The teenage shooter who opened fire at Saugus High School died Friday of a self-inflicted gunshot wound as investigators seized unregistered firearms from his home and tried to determine the origin of the handgun used in the deadly attack.
Authorities say Nathaniel Berhow carried out the violence at the Santa Clarita campus on his 16th birthday after being dropped off at school by his mother. School surveillance video reviewed by law enforcement shows a boy pulling a pistol from his backpack and opening fire in the quad, killing a 15-year-old girl and a 14-year-old boy and wounding three others in an attack that lasted 16 seconds.
At one point during the gunfire, the weapon jammed and the shooter cleared the firearm before he continued firing. He appeared to know how many shots he had fired and left the final round for himself, ending the attack with a gunshot to his head, said Los Angeles County Sheriff Alex Villanueva. The teen died of that wound Friday afternoon.
Investigators think the attack was planned but said they do not suspect specific students were targeted. Investigators seized unregistered firearms from the home of a teen who authorities say opened fire at Saugus High School on Thursday, killing two students, but officials are still trying to determine the origin of the handgun used in the deadly attack.
"He seemed very familiar with firing the weapon," Villanueva said. He added that the shooting was not a "spur of the moment act," but officials have not determined a motive.
Federal and state investigators are also trying to determine whether the handgun used by the suspect was made from parts purchased separately and then assembled, law enforcement sources told the Los Angeles Times.
These so-called ghost guns are unserialized weapons manufactured from parts that can be ordered through the mail or machined parts acquired from underground makers.
The sources said the gun design appears to be unusual but emphasized that officials don't know its origins at this time.
Investigators found several firearms during a search of the teen's home, and some were not registered. Villanueva did not specify what types of guns were recovered. The L.A. County Sheriff's Department is working with the federal Bureau of Alcohol, Tobacco, Firearms and Explosives to trace the origins of the .45-caliber handgun used in the shooting.
The suspect, who authorities said ended the outburst of violence with a bullet to his head, was listed in critical condition Friday morning, officials said.
Deputy James Callahan, a school resource officer at Saugus, said he was on his way to campus when the shooter call went out Thursday. When he arrived minutes later, he rushed to help students wounded in the quad along with other off-duty law enforcement officers who were already rendering aid.
"When you're a school resource deputy, you take a lot of pride in keeping your campus secure," he said. "You never think a tragic thing like this is going to happen."
A day after the gunfire erupted, students, parents and law enforcement officers described the tightknit community as being in a state of mourning. Many continued to struggle with the violence that had unfolded.
Xitlali Rodriguez had been sitting in her first-period digital photo class when she heard the gunshots ring out. The classroom door was wide open, she said, and she was just one building away from the quad where the shooter opened fire.
The 16-year-old thought she was going to die. The students did their best to keep a low profile: They closed the door, shut off the lights and hid in the room. Everyone was texting family and friends. She watched as some cried silently while others hugged, trying to comfort one another.
Rodriguez said she had to talk to the emotional support counselors at school, who told her she was suffering from acute post-traumatic stress disorder.
"I'm thankful to be around family, and I'm happy that I am safe," she said, "but I'm scared to go to school or large public areas now, and no one should have to feel like that."
Coroner's officials on Friday identified the 15-year-old girl who died in the shooting as Gracie Anne Muehlberger and the 14-year-old boy who died as Dominic Blackwell.
Two teenage girls who were wounded in the shooting remained hospitalized Friday but are expected to recover from their injuries. A 15-year-old girl arrived Thursday at Providence Holy Cross Medical Center with a gunshot wound below her belly button, doctors say. The bullet, which had lodged in her hip, was removed by surgeons.
A 14-year-old girl arrived at the same hospital with gunshot wounds to her left shoulder and lower abdomen. Both girls are expected to be released in the next day or two, doctors say. The teens are staying in the same room and are surrounded by their families.
"Once we were done with the work-up, they were both sitting up, smiling and talking," Dr. Boris Borazjani said during a morning news conference at the hospital.
One student, a 14-year-old boy, was treated and released Thursday afternoon from the hospital. His specific injuries were not provided.
All schools in the William S. Hart Union High School District were closed Friday out of respect for the victims and their families. However, district counselors were being made available for students and staff at Grace Baptist Church, Deputy Superintendent Mike Kuhlman said.
"The gun violence experienced across our nation, and all too often on school campuses, has prompted our district, like others, to conduct staff and student trainings for these unthinkable events," he said in a statement. "We take the training seriously; we prayed that we would never need it. Yet today, our brilliant staff bravely and vigilantly went into action."
Detectives have conducted 40 interviews and still have six to go in their efforts to piece together what led up to Thursday's shooting. They've also searched the teenage suspect's papers and computer hard drives for any clues as to a motive, but so far, none has emerged. The teen didn't leave behind a suicide note or manifesto detailing any plans, Sheriff's Capt. Kent Wegener said Friday.
Friends and neighbors of the suspect were stunned, saying the teen showed no signs of aggression. He ran junior varsity cross-country and helped younger members in his Boy Scout troop. Classmates described him as being very intelligent, an academic achiever who often received the highest marks in his classes.
"He was pretty funny too," Brooke Risley, 16, said. "He had a higher-level type of humor that often I couldn't even get the joke 'cause it was above my head."
However, public records and a high-ranking law enforcement source indicated there were signs of trouble at home.
His family life in Santa Clarita was upended by his father's sudden death in December 2017, acquaintances said. More recently, a source told The Times that the boy was having problems with his girlfriend, who was his emotional anchor.
The teen's father, Mark Berhow, was arrested on suspicion of driving under the influence in 2013 and 2015 and pleaded no contest twice. The second time, he was sentenced to 45 days in jail and five years' probation.
According to jail records, he was also booked in 2015 on suspicion of attempted battery of a spouse. The Los Angeles County district attorney's office declined to file charges in that case, citing insufficient evidence.
A judge granted physical custody of the boy to his mother in August 2016, even though both parents still appeared to live in the family's small ranch home on Sycamore Creek Drive.
"It's a tough day here in Santa Clarita," Villanueva said. "Grab your kid, hold them a little tighter and make sure they do the right things when they're in school."
Authorities are asking any witnesses who have not already spoken to police to contact the Los Angeles County Sheriff's Department's Homicide Bureau at (323) 890-5500.
