Arcata High School was shut down after someone called in a bomb threat in Friday afternoon, but no explosives were found, police said.

Arcata Police Department Lt. Ryan Peterson said a bomb threat was called in to the school during students’ lunchtime, which made evacuation procedures “kind of chaotic.”

Many students had vehicles in the school parking lot and had to return to pick them up, he said. “It made a confusing scene for a little bit,” Peterson said.

He didn’t provide many details about the person who called the threat in around 12:30 p.m. “We’re not going to release that because of the investigation,” he said. “We need to get to the bottom of this, find out who did this and why and they need to be prosecuted — whether it’s a juvenile or an adult, it doesn’t matter.”

Students on campus were evacuated to nearby Stewart Park and were later dismissed for the rest of the day, Arcata High freshman Eli Beiser said. “It’s not that exciting,” the 15-year-old said. “It was massive for the first second.”

Arcata Police Chief Randy Mendosa said the threat was likely a hoax, which is typical for high schools to receive. “It’s kind of an unfortunate prank that happens too often,” he said.

Personnel from APD, Humboldt State University’s police department, the Arcata Fire Protection District and the Humboldt County Sheriff’s Office responded to the high school, Peterson said, and the school was searched, to no avail.

A room-by-room, closet-by-closet search was done, he said. “It was kind of time-consuming and tedious,” Peterson said. “If it is a joke, it’s a bad one and could potentially cost someone’s life if there was some sort of emergency elsewhere and our response is delayed because of a joke.”

The APD responds to bomb threats a few times a year, Peterson said, but they’re not too common. “But the police response is the same and it has to be,” he said. “You can’t be complacent, it just requires a lot of resources to have that response and it’s costly to the taxpayers.

“My fear is that you have someone playing a joke, and somebody somewhere in town has a heart attack, or their house is getting broken into — what happens then?”

The sweep through campus took about two hours, Peterson said.

Sophomore Michael Tharp said he didn’t see the logic in the threat.

“If you’re going to bomb a school, why would you call?”