OKLAHOMA CITY - The former student who allegedly brought a gun onto campus at U.S. Grant High School in Oklahoma City is in custody.

Schools officials say the former student, who has only been identified as a male, was found to be carrying the gun inside a backpack. When confronted by a school resource officer, the former student took off on foot. The gun was taken before the student ran. No injuries were reported during this incident.

The school was first placed on lockdown. Around 11:30 a.m., the school moved from a "lockdown" to a "lockout". School officials told parents they could pick up their children at the designated area, but were not allowed inside the school building.

U.S. Grant High School is located in the 5000 block of S. Pennsylvania Avenue. Nearby elementary schools were placed on "lockout" while police searched for the former student. The lockouts at the other schools were lifted just before noon.

According to school officials, a “lockdown” means that no one is allowed in or out of the building and all students/staff will remain in locked classrooms or other safe areas until law enforcement deems the facility safe.

A “lockout” means that classes proceed as usual with no one allowed to come in or out.

School officials say all after school activities have been canceled today as a precaution.

Thursday afternoon, U.S. Grant High School officials held a press conference detailing the events leading up to the arrest of the former student. 

Keep checking with News 9 and News9.com for more information.