Police on Tuesday said they believe it’s likely that Santino William Legan acted alone when he opened fire at the annual Gilroy Garlic Festival, killing three people and wounding a dozen more.

Investigators are still following up on leads from witnesses who said they spotted a second suspect at the gathering in southern California Sunday — but the probe so far has led them to believe there wasn’t another person involved, Gilroy Police Chief Scot Smithee said in an afternoon press conference.

Smithee said investigators tracked the 19-year-old gunman’s movements around town and that surveillance video shows him visiting various stores alone, “supporting the thought that he acted on his own.”

Investigators found a shotgun in Legan’s car, which was parked northeast of the Christmas Hill Park festival grounds, Smithee said.

They also dug up a bag full of ammunition in a creek near the garlic celebration.

Police say Legan got into the festival via the creek, by cutting a whole in a fenced area. He was shot dead by officers within one minute of opening fire, authorities said.

Legan legally bought the AK-47-style gun he used to carry out his rampage and the shotgun in Nevada, police said.

Authorities said they seized a bulletproof vest, an empty shotgun, a gas mask and empty ammunition boxes from Legan’s Nevada apartment.

Officials also found pamphlets on guns and a sack full of ammo casings at the home, the Mineral County district attorney’s office said Tuesday.

There’s still no word on the gunman’s motive.

Legan had posted hate-filled messages against mixed-race people on social media before his rampage.

Officials said Tuesday there is no indication that he specifically targeted people of color.

The investigation is ongoing and will be “for quite a long time,” Smithee said.