July 29 (UPI) -- California authorities on Monday identified the gunman they say opened fire and killed three people -- including a 6-year-old boy -- at a Bay Area festival.
The gunfire erupted Sunday at the Gilroy Garlic Festival, an annual fixture on the city's summer calendar. The three dead were the boy, identified by his family as Steven Romero, a 13-year-old girl and a man in his 20s, neither of whom have been identified. Gilroy is located 30 miles southeast of San Jose and 70 miles southeast of San Francisco.
Gilroy police Chief Scot Smithee identified the shooter as 19-year-old Santino William Legan, a native of Gilroy, during a news conference Monday.
Smithee said the shooter began firing with an SKS rifle, similar to an AK-47, and had entered the event by cutting through a fence to avoid security. Smithee said the police response was quick, and that three officers shot and killed the gunman within a minute of receiving the first reports of gunfire.
Legan purchased the rifle legally in Nevada, where he had been living, Smithee added.
Joy Alexiou, a spokeswoman for the Santa Clara County Public Health System, said several people received gunshot wounds and were transported to two hospitals. Twelve people were injured, officials said.
The motive behind the shooting was not known, Smithee said.
Craig Fair, deputy special agent in charge of the FBI in San Francisco, said Monday that his agency was brought in to assist Gilroy police in determining a motive, and the shooter's ideological leanings or affiliation with any groups.
He said some 30 agents were collecting evidence from "many" acres of land.
Gilroy Mayor Roland Velasco called the shooting a "tragic and senseless crime."
"I want to express my extreme shock and sadness about what happened here today," he said Sunday.
Appearing at Monday's news conference, Velasco thanked the first responders who came to the crime scene.
"Mass gun violence is an epidemic in the United States and yet one never imagines such a thing can happen here in our beautiful community," he said.
Smithee said a manhunt was underway for a possible second suspect, though that person's role wasn't known.
"We believe there was a second individual involved in some way, we just don't know in what way," he said during a press conference Sunday.
The Bureau of Alcohol, Tobacco, Firearms and Explosives' San Francisco office also said it is investigating.
"ATF sends our sincerest condolences to the victims, their families and friends and the entire Gilroy community," the bureau said Monday. "We will continue to work alongside our local, state and federal partners throughout the investigation."
President Donald Trump on Monday called the attack "horrific."
"While families were spending time together at a local festival, a wicked murderer opened fire and killed three innocent citizens, including a young child," he told reporters at the White House. "We grieve for their families and we ask that God will comfort them with his overflowing mercy and grace.
"We reaffirm our national will to answer violence with the courage, determination and resolve of one American family. We will continue to work together as communities and as citizens to stop evil, prevent violence, and protect the safety of all Americans."
The shooting occurred during the final day of the three-day annual Gilroy Garlic Festival, which began in 1979.
Video from the shooting shows people screaming as they try to hide under tables, behind tents and over fences.