A 15-year-old student is in custody and faces a felony charge following a report that a person had a gun on campus at Lanier High School, Austin ISD Police Chief Ashley Gonzalez said.
All students and staff are safe, and regular activities had resumed at the North Austin school following about an hour-long lockdown.
At a news conference, Gonzalez said a student had flashed a gun in front of students and a staff member around noon, then ran after a school resource officer got involved.
The Austin Police Department said it received a request for assistance around 12:03 p.m. The student was located by the police K-9 unit.
An airsoft gun that looked "exactly like a handgun" was found next to the student, Gonzalez said. "It was not a real gun."
He said the student will be charged with a felony for making a terroristic threat.
This story has been updated.