‘‘That's going to be haunting me for a long time,'' said Chris Reynolds, 29, who heard the threats and didn't report them.
Williams, held in a juvenile facility Tuesday, will be charged as an adult with murder, assault with a deadly weapon and gun possession, said District Attorney Paul Pfingst. The adult prosecution is mandatory under a ballot measure approved last year, and the boy could face multiple life terms. Arraignment was set for Wednesday.
Pfingst said the gun belonged to Williams' father, Charles, a lab technician at the Naval Medical Center-San Diego, since July. Sheriff's and FBI officials Monday night searched the Williams' apartment and said they removed seven rifles, a computer, a plastic crate filled with papers and files, and about a half dozen bags filled with evidence.
The slain students were identified as Bryan Zuckor, 14, and Randy Gordon, 17, sheriff's Lt. Jerry Lewis said. Wounded were 11 other students and two adults, a student teacher and a campus security worker. Four students and the two adults remained hospitalized Tuesday, all in good or fair condition.
The shooting happened about 9:20 a.m. Monday in this overwhelmingly white, middle-class suburb of San Diego, a town that prides itself on its country atmosphere and low crime rate.
Lots of youngsters were out and about, as one ‘‘block'' of students who start early in the day headed to their next classes and another group — Williams' ‘‘block'' — arrived for their first classes of the day.
The boy shot two people in a restroom, then walked into a quad and fired randomly, Lewis said. He stopped to reload as many as four times, getting off 30 or more shots, Lewis said.
‘‘It was total chaos. People were trying to take cover,'' said student John Schardt, 17, who was in a nearby classroom when the shooting started in a boys' restroom. One thing he noticed: The youthful shooter had a smile on his face.
‘‘Pop, pop, pop and everyone started ducking,'' recalled student Nika Ocen-Odoge.
Barry Gibson, 18, said he ran at the sound, then returned with two others when they saw a friend fall to the ground. The friend rolled onto his side, spitting up blood.
‘‘We were asking him, ‘Are you OK?''' Gibson told the Los Angeles Times. Amid another burst of fire, Gibson ran. ‘‘I got hit in the leg,'' he said. ‘‘It went numb.''
Authorities have said little about a possible motive for the rampage, but the suspect's life abounds in the kind of warning signs that have become as familiar as the TV images of frightened students being herded to safety from the presumed safe harbor of a suburban school.
Williams, whose parents are divorced, occasionally visited his mother, Linda Wells, in North Augusta, S.C. He and his father moved to California from Frederick County, Md., last year.
He's a skinny kid, a skateboarder ‘‘wannabe'' according to some friends. There's talk of recent scrapes with booze and a girl, a breakup, and a beating by another teen-ager at the skateboard park where he hung out. His skateboard was stolen twice, one friend recalled.
‘‘He was picked on all the time,'' student Jessica Moore said. ‘‘He was picked on because he was one of the scrawniest guys. People called him freak, dork, nerd, stuff like that.''
While staying overnight Saturday with his friend Joshua Stevens, 15, Williams spoke specifically about shooting up the school, according to both Stevens and Reynolds, who is dating Stevens' mother.
Both moved tentatively to head off trouble, but failed.
‘‘My friend A.J. patted him down this morning for guns, but he said he was joking,'' Stevens told The San Diego Union-Tribune. ‘‘I guess he had (the gun) by his crotch.''
Reynolds said he warned Williams: ‘‘I even mentioned Columbine to him. I said I don't want a Columbine here at Santana. But he said, ‘No, nothing will happen, I'm just joking,''' Reynolds told the AP.
Reynolds tried to call Williams' father twice on Sunday, but gave up after getting no answer and then a busy signal, the Los Angeles Times reported.
There have been signs since the 1999 Columbine High massacre that left 15 dead in Colorado that teens and those around them have become more willing to report threatening behavior. There have been at least four incidents around the country in recent months where students reported threats and possibly averted violent episodes at school.
Why not at Santana High?
Vanessa Willis, a 15-year-old friend and neighbor, of Williams, summed up the response in explaining why she ignored the boy's warning to stay home because he might bring a gun to school: ‘‘I said, ‘Whatever.' I didn't take him serious.''