GILROY (KPIX) — A manhunt is underway for multiple gunmen, not just a single shooter, in the investigation into a Halloween party shooting that left one person dead and three others injured at the home of a Gilroy councilwoman.

“Based on information to this point, it is believed there were at least two shooting suspects, with Calderon being one of the suspects,” the Gilroy Police Department wrote in a press release.

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Police arrested 19-year-old Benjamin David Calderon on Saturday, less than 24 hours after the deadly shooting.

Detectives said it appears the shooting was triggered by an argument at the party.

The Halloween party took place at the home of Gilroy City Councilwoman Rebecca Armendariz.

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“As soon as I arrived, I saw the people and my friend and I just decided to leave,” says Nate Huerta.

Huerta says he had a bad feeling about the party even before the bullets started flying. He says he was concerned about the mix of alcohol and what he describes as a rough crowd who he feared might be armed.

He says he left the party well before the shooting but later learned that a friend, 18-year-old Michael Zuniga-Macias, had been caught in the crossfire and was killed.

“He just got caught in the middle of it. He was caught in the wrong place at the wrong time. It’s unfortunate. That’s why it’s so sad because he had nothing to do with it,” Huerta said.

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There was a growing memorial of candles and flowers arranged outside councilmember Armendariz’ home. Monday evening, a group of roughly 50 mourners gathered outside the home for a prayer vigil for the victims.