Authorities said a gunman armed with an "assault-style rifle" appeared to randomly target people at a food festival in Gilroy, California. The man shot and killed three people and injured at least 12 others before police shot him dead on Sunday.Among the dead was six-year-old Stephen Romero. His father Alberto Romero told an NBC television station "My son had his whole life to live and he was only 6." Romero added that his wife and his mother-in-law were among those injured in the attack.Officials have not released the names of the other two victims, a 13-year-old girl and a man in his 20s.Gilroy police chief Scot Smithee identified the gunman as 19-year-old Santino William Legan. He said police had a command center at the event for security but the gunman cut through a fence to avoid metal detectors and other security measures.The man then fired on a crowd eating and listening to music. The gun used in the attack was bought in the state of Nevada earlier this month.Smithee said police responded within one minute and killed the suspect. It ended "very quickly," he said, "We had thousands of people there. It could have gone so much worse so fast."Some witnesses reported a second suspect. However, it is unclear if that person was carrying a weapon or provided aid to the gunman. Police are continuing their search for the other possible suspect.Video that has spread on social media shows crowds of people running in fear and confusion as the sound of gunfire is heard. News reports say a teenage girl said she thought the gunfire was fireworks, but then saw an injured person.The Gilroy Garlic Festival celebrates food, cooking and music and was established in 1979. The three-day festival attracts about 100,000 people. The town, known as the "garlic capital of the world," is about 130 kilometers southeast of San Francisco.The festival is operated by volunteers. It bars weapons of any kind and also bars signs associated with gangs.