Garlic Festival .
© Noah Berger/AP
A road sign marks the Garlic Festival parking area in Gilroy, Calif., July 28, 2019.
A 19-year-old was identified Monday as the suspected gunman in the California festival shooting that killed at least three people and injured more than a dozen others.

Gunshots rang out Sunday just before 6 p.m. local time at the popular Gilroy Garlic Festival in the city of Gilroy, some 80 miles southeast of San Francisco.

The shooter was identified as Santino William Legan, law enforcement sources confirmed to ABC News. Investigators responded the home of Legan's father in Gilroy hours after the shooting, sources said.

A 6-year-old boy was among those killed, the boy's grandmother told ABC San Francisco station KGO.

Garlic Festival
© Philip Pacheco/AFP/Getty Images
Police vehicles arrive on the scene of the investigation following a deadly shooting at the Gilroy Garlic Festival in Gilroy, 80 miles south of San Francisco, Calif., July 28, 2019.
"He was a really happy, loving boy," Maribel Romero told KGO. "I want justice for my grandson."

Gilroy Police Chief Scot Smithee told reporters at a late-night press conference that officers engaged the suspected gunman within a minute of the shooting and killed him.

A law enforcement official told ABC News that authorities are searching for that individual's motive in the attack. Officials were investigating whether there were multiple suspects.

Santa Clara Valley Medical Center and St. Louise Regional Hospital received a total of 11 patients with gunshot wounds from the shooting, according to Joy Alexiou, a public information officer at Santa Clara Valley Health System, which runs both hospitals.

One of the patients died, while three others were treated and discharged. The conditions of the remaining patients with gunshot wounds vary from fair to serious to critical, with some undergoing surgery. Eight other patients were admitted and treated for non-gunshot injuries, Alexiou told ABC News.

Candace Marquez and Cheryl Low, who were working at a festival booth, said they heard a "pop" and saw a man with a gun walking toward the tent.

"His gun was pointed to the ground, he was trying to put another clip in it and then he started walking to the left, away from us, and he started shooting," Marquez told ABC News chief anchor George Stephanopoulos in an interview Monday on "Good Morning America."

Marquez said her niece was at the tent and stayed with her boss' 3-year-old son.

"My niece was actually a hero," Marquez said. "She grabbed him and hid him under the table so he didn't get shot."

Low told ABC News that her boss and husband were both shot and taken to the hospital.

"One's in stable and one's in critical condition," Low said. "It's touch and go right now."

Marquez and Low told ABC News that the gunman, who appeared to be alone, didn't say anything to anyone and seemed to be shooting at random.

"The next thing I saw, police had already shot and killed him," Low said.

Steve Janisch, a chef at the festival, said he was cleaning up and getting ready to leave when the gunshots started.

"I heard the shots, and got as many [of] as my guys, and got behind shelter in the alley," Janisch told ABC News. "I saw many people running in fear. Once we rounded everybody up out in the parking lot, we headed out per the direction of the authorities. I drove a mother and her two daughters safely to their car."