At first, when it began, it was lost to the soundtrack of another Friday night in this bluff-top college town: screeching tires and what sounded like fireworks.
But then — shattered glass. Sirens. Screams.
Within 10 minutes, it was done — seven dead, 13 wounded, a tormented young man slumped at the wheel of a shattered BMW, a gunshot wound to his head, three semiautomatic handguns and more than 400 rounds of ammunition at his side.
Behind him, there were 10 distinct crime scenes in a single square mile — skateboarders and bikers run down and tossed into the air; bullets bursting through the windows of shops; police officers tackling pedestrians and hauling them indoors to protect them; two young women dying on the lawn of a sorority.
For months, Elliot Rodger, 22, had posed behind the wheel of that same BMW, posting videos of himself on social media.
The son of a Hollywood director, he was born to a rarefied world, but he had been suffocating in sadness and self-pity, lashing out at those he felt had rejected him. To the popular kids, the sorority sisters, "the brutes," he had promised "a day of retribution."
On Friday, the authorities said, it arrived. Santa Barbara County Sheriff Bill Brown called the rampage "premeditated mass murder," the "work of a madman."
A 137-page diatribe Rodger emailed to an online acquaintance before the killings appeared to shore up those contentions.
In the document, Rodger envisioned a future in which sexuality no longer existed, and women were housed in concentration camps. He pledged to do "everything in my power to destroy everything I cannot have."
"I am the true victim in all of this," he added. "I am the good guy. Humanity struck at me first."
Rodger's family, through an attorney, released a statement offering its "deepest compassion and sympathy to the families involved in this terrible tragedy."
"We are experiencing the most inconceivable pain, and our hearts go out to everybody involved," the family said.
On Saturday, marine clouds clung to the terraced bluffs of Santa Barbara County, creating a drab and eerie tableau. Bleary residents walked quietly through the streets, peering through bullet holes in windows, watching as scores of law enforcement officers combed through the residential neighborhood where the BMW crashed.
The still was punctuated by moments of heartbreak. The father of one victim, 20-year-old Christopher Martinez, collapsed in the arms of a police chaplain after he described how his family was "lost and broken."
Martinez, a sophomore at UC Santa Barbara, was an English major and planned to attend law school. He was shot and killed when he went to a convenience store for a snack, 45 minutes after speaking with his father on the phone.
"You don't think it will happen to your child, until it does," said his father, Richard Martinez.
The elder Martinez lashed out at gun-rights advocates and politicians who won't stand up to them. He held in his hands a photo of his son as a child, smiling in a baseball uniform.
Elliot Rodger saw numerous therapists, according to his family, and was on the autism spectrum.
He posted videos decrying the "cruelty of humanity" and recently made a "citizen's arrest" after accusing a roommate of stealing three candles with a value of $22.
Separately, just a month ago, family members asked sheriff's deputies to check on his welfare. When they arrived, the sheriff said, officers interviewed him and found him to be polite and lucid.