Authorities identified Santino William Legan, 19, as the man who shot and killed three people at the Gilroy Garlic Festival, two law enforcement officials told CNN on Monday.
A 6-year-old boy was among the dead, and another 12 people were injured when the gunman opened fire on the crowds attending the outdoor festival around 5:40 p.m. local time, according to Gilroy Police Chief Scot Smithee. The gunman was killed by police on the scene, authorities said.
Monday morning, several police cars were outside the home of Legan's father in Gilroy.
What officials say about the shooter
The shooter had an assault-style rifle and appeared to shoot at random, Smithee said. Officers on the scene shot and killed the suspect within one minute of the shooting, according to police.
Witnesses reported seeing a second individual who has not yet been identified or found. A manhunt is underway for this possible second suspect, though the extent to which this second person may have been involved or participated in the shooting is unknown, said Smithee.
Police believe the suspects cut through a fence near the creek with a tool to enter onto the event grounds in Gilroy, which is about 30 miles south of San Jose. There were no posted security cameras at the festival, according to Smithee.
The FBI Evidence Response Team from San Francisco has arrived and is currently processing the scene at the festival, according to the official source. The Bureau of Alcohol, Tobacco, Firearms and Explosives is also there, along with various state and local police and fire departments, though no further information is available.
Instagram posts hours before attack
An Instagram account bearing the suspect's name, which was created four days ago, posted two messages shortly before the attack began.
One included a photograph of people walking around the Garlic Festival with the words "Ayyy garlic festival time Come get wasted on overpriced sh**."
The other, which included a photo of Smokey the Bear holding a sign saying "Fire Danger High Today," stated: "Read Might is Right by Ragnar Redbeard. Why overcrowd towns and pave more open space to make room for hordes of mestizos and Silicon Valley white tw**s?"
A mestizo is a person of mixed descent, commonly white and Hispanic or white and American Indian.
"Right is Might," first published in the late 1800's, has been described as a white supremacist text that promotes anarchy while vilifying Christianity. The book calls Jesus the "true Prince of Evil" and says that the natural order is a world at war in which the strong must vanquish the weak and white men must rule over those of color.
Julissa Contreras, who was standing within 20 feet of the shooter, told CNN's Natalie Allen the gunman "looked like the average guy.
"White, about in his 30s, under 6 feet. He was wearing tactical gear, had a baseball cap on, sunglasses, and he had a semi-automatic rifle. He was dressed for what he was there to do."
Contreras also said that "he didn't look angry," though she added that his "expression wasn't really something I could read on his face but he seemed very well-versed in what he was doing... and he seemed confident in his use of the gun."
Members of the band Tin Man, who were starting an encore when the shooting happened, told CNN the gunman was carrying a rifle and wearing a green shirt with a gray handkerchief tied around his neck. They also said that he sprayed gunfire from side to side with no direct target, creating pandemonium among the crowd.
What is not known
Police have not yet provided their own description of the shooter or what he was wearing and a possible motive for the shooting also remains unknown.
Josh Campbell, a former FBI supervisory special agent, told CNN's Jim Sciutto that witnesses provided information to the police about a possible second suspect but "we know there's almost always never a second shooter" in these types of mass killings.
Campbell noted the shooter was prepared, as demonstrated by the fact that he cut through the fence to avoid security and metal detectors. Among the questions that need to be answered is why the shooter wanted to get into the annual food festival, Campbell said, adding that the answer would speak to the gunman's motive.
Law enforcement have already recovered a firearm and rifle ammunition from the shooting, a law enforcement official told CNN, but they have not provided the exact make of the firearm used.