Timothy Bradford Cole, 43, of Huntington Beach, was arrested in the aftermath of the collision, which was reported after 10 p.m. Monday near Ellis Avenue and Magnolia Street.
Cole allegedly led police on a high-speed chase in a Dodge Ram pickup and ran a red light before slamming into the BMW SUV.
A 25-year-old Huntington Beach woman - a passenger in the BMW - died on the way to a trauma center, police said. Two other victims in the SUV were taken to a hospital and are expected to survive.
At least 1 killed after possible chase ends in violent crash in Fountain Valley
"To know that somebody's little girl is not coming back home is just extra unbearable. I lost a 31-year-old daughter last February, and so this is just too much," said Shane Schmidt, who identified Cole as his future brother-in-law.
Schmidt is trying to wrap his head around the tragic events that unfolded Monday night.
"It's the definition of senseless," he said. "This makes no sense."
Officers initially responded to a report of arson at Schmidt's home in the 18000 block of Arches Court around 7:30 p.m.
Screenshots from Schmidt's Ring doorbell camera showed a fire outside of his home. The footage also showed the fire was intentionally set.
"I saw the person that I know to be my future brother-in-law light my house on fire," Schmidt said.
Neighbors helped put out the flames and the home was not damaged.
"The suspect was gone upon officer arrival. Investigation revealed because of an ongoing domestic dispute, a known suspect doused a bush adjacent to the home with lighter fluid and lit it on fire," police said in a news release.
Officers spotted Cole's truck hours later in a parking lot in the 17900 block of Brookhurst Street, police said. Officers tried to pull him over, but Cole allegedly led them on a pursuit that lasted about a minute.
"Unfortunately, the suspect ran the red light, at which point he collided with a white BMW occupied by three individuals," Fountain Valley police Sgt. Henry Hsu said.
Cole was taken into custody without incident.
Schmidt said Cole is troubled. He doesn't know what triggered him to lash out.
"Absolutely mortified, disgusted, so sad and heartbroken for that family, all of the families, our family on a different level," Schmidt said.
Cole was taken to a Long Beach hospital in serious condition. He faces multiple charges.