July 31 (UPI) -- Northern California authorities say the man who shot three people dead at a summer festival this week, including two children, acted alone without help from anyone else.
Investigators said Santino William Legan didn't conspire with anyone to attack the annual garlic festival in Gilroy on Sunday, where he opened fire with an AK-47-type rifle. A 6-year-old boy, 13-year-old girl and a man were killed before Legan shot himself. Gilroy, a city of about 60,000 residents, is located 30 miles southeast of San Jose.
Authorities said immediately after Sunday's shooting they were actively searching for a second suspect, but did not specify what role they believed the accomplice played.
"Our investigation is leading us more and more to believe that there was not a second person involved," Gilroy Police Chief Scot Smithee told reporters Tuesday.
Smithee said surveillance video from nearby stores show Legan by himself. He didn't specify what initially led police to suspect the 19-year-old shooter had an accomplice. Investigators are still unsure of a motive, but are examining potential white supremacist or anti-Semitic ties.
"We continue to try to understand who the shooter is, what motivated him, and if he was aligned with any particular ideology," said Craig Fair, deputy special agent in charge of the FBI's San Francisco field office.
Police said a search of Legan's apartment in Hawthorne, Nev., turned up evidence that indicated he may have been planning a larger attack. They also found reading material on white supremacy and radical Islam, a gas mask, bulletproof vest and empty boxes of ammunition. Legan grew up in Gilroy but moved to Nevada last spring, police said.
Investigators are also examining Legan's digital footprint for possible clues.
A recent Instagram post police attribute to Legan showed a sign of Smokey the Bear warning about fire danger with a caption that promoted an 1896 novel that advocates anarchism and amorality and cites social Darwinism to justify racism, slavery and colonialism. The book is popular among white supremacists.
"A review of digital media historically has been very revealing in terms of somebody's mindset, ideological beliefs, intentions," Fair said.