A man who stabbed four people at UC Merced last year before he was fatally shot by police appears to have been inspired by the militant group Islamic State but acted alone, the FBI said Thursday.
The FBI released a statement saying a review of Faisal Mohammad's electronic devices found that he drew inspiration from terrorist propaganda and may have been "self-radicalized" before the Nov. 4, 2015, attack.
"His laptop contained pro-ISIL propaganda, and he had visited ISIL and other extremist websites in the weeks prior to his attack," the agency said, using an acronym for the extremist group, which is also called ISIS.
The FBI said Mohammad, a freshman at the university from Santa Clara, began his preparations for the rampage at least a week beforehand. No information was found that showed he was helped or directed by another person or group in carrying out the stabbings, the FBI said.
News of the Islamic State link comes nearly four months after the San Bernardino attack that killed 14 people. The FBI said the two shooters in that incident were also self-radicalized and inspired by Middle Eastern terrorist groups. An Islamic State propaganda magazine later praised the couple as martyrs.
Mohammad's alleged connection to the Sunni Muslim extremist group was "new information," said Daniel Mayfield, an attorney representing Mohammad's family.
He said the family had not been able to review investigative reports on the incident. From the FBI's brief statement about the conclusions of the inquiry, Mayfield said, it was unclear what type of pro-Islamic State propaganda was found on Mohammad's computer.
"It could be anything from a 17-year-old trolling the Internet to a class assignment to something nefarious," Mayfield told The Times. "What can you say ... until we get the computers back?"
Investigators seized property belonging to family and friends of Mohammad after the stabbing, but that was returned after nothing notable was found, Mayfield said.
In a statement issued by Mayfield, the family said Mohammad's actions were a sharp departure from the boy they knew: "Faisal was always quiet, respectful and studious."
Starting shortly before 8 a.m. at the Central Valley university, Mohammad, 18, stabbed four people before being shot and killed by a campus police officer.
Investigators found a "two-page, handwritten manifesto" in the assailant's pocket during an autopsy, Merced County Sheriff Vern Warnke said at a news conference. The document detailed an elaborate "script" for the attack, Warnke said.
Mohammad had planned to go into a classroom and force another student to help him tie his classmates' hands with zip-tie handcuffs, Warnke said. Mohammad listed some students by name.
He then planned to put petroleum jelly into clear bags, cut holes in the bags and squirt the substance onto the floor, making "kind of a slip-and-slide" that would make it difficult for anyone who entered the room, the sheriff said.
In the note, Mohammad said he anticipated a confrontation with police and planned to steal an officer's gun before leaving the classroom to "do other tragedies on campus," the sheriff said.
That plan was foiled by a construction worker, who entered the classroom and "befuddled" Mohammad, Warnke said last year.
Mohammad's apparent inspiration by Islamic State marks a sharp contrast to what the sheriff said last year: that Mohammad was angry about getting kicked out of a study group.
"There is still nothing to indicate ... that this is anything other than a teenage boy who got upset with fellow classmates and took it to the extreme," Warnke said.
In Thursday's statement, the FBI signaled a note of uncertainty: "It may never be possible to definitively determine why he chose to attack people on the UC Merced campus."