An 18-year-old man was arrested after allegedly fatally shooting his mother inside their Fontana home on Thursday morning, police said.
Officers found Fabian Dusten Cardona crouching behind a parked vehicle on the street with an AR-15-style assault weapon after responding to a report of shots fired at a home in the 14600 block of Mountain High Drive around 1:45 a.m., Fontana police said.
Cardona initially refused to drop the firearm, but surrendered after deputies fired a warning shot, authorities said.
No one was struck by the gunfire.
Upon searching Cardona's home, officers discovered his 50-year-old mother inside with multiple gunshot wounds in her torso.
The mother — whose name was not released — was taken to a local hospital, where she died from her injuries.
A 12-year-old child was inside the home at the time of the shooting and was the one who called 911 to report what had happened, police said.
Authorities received additional calls about shots being fired inside the home while officers were on the way to the scene, Officer Richard Guerrero said. After shooting his mother, police said Cardona walked outside and banged on the doors of two other homes.
Brenda Ceniceros, who lives on the street, said one of those residences was hers.
“We just kind of heard some pounding, but we didn’t know what it was,” she said.
Guerrero said one neighbor had spotted "someone with a rifle near the street."
There was also evidence indicating that the suspect shot at unoccupied Spectrum van several times.
Julian Aguirre, who lives next door to Cardona’s family, said the gunman was arrested on his front lawn.
“I don’t know what made him click like that," Aguirre told KTLA. "It definitely was out of his character.”
Aguirre said he'd been unaware Cardona was a gun owner until early Thursday morning.
“We never even knew he was armed," he said. "To be honest, this seemed like a safe neighborhood. We didn’t think a lot of people around here would be armed or anything like that.”
Neighbor Jeremiah Schultz, who saw Cardona being taken into custody, said the suspect “seemed a little disoriented” at the time and had “slurred speech.”
Detectives are now trying to determine a motive for the shooting.
One neighbor told KTLA the slain mother had recently tried to kick Cardona out of the house.
Inmate records showed the 18-year-old was being held without bail and scheduled to appear in court next Tuesday, April 2.
KTLA's Erika Martin contributed to this report.