A man who said he had a gun went into a classroom at Sequoia High School yesterday, grabbed a male student and tried to pull him out of the room, Redwood City police said.
A teacher physically intervened, causing the man to run through the campus, police said.
The school was put on lockdown around 2 p.m. while officers searched the campus.
They found Trey Duus, 24, holding an umbrella. He had punched a hole in a bathroom wall and stole a printer cartridge, police said.
Duus was taken to a hospital and then jail, police said.