A spokesperson with the Highway Patrol confirmed someone called in a bomb threat to its dispatchers, which included a vehicle description.

After evacuating the premises, which are near the state Capitol in Oklahoma City, the Highway Patrol set up a perimeter and stopped a vehicle that matched the caller’s description. They took the driver, who they believe made the call, into custody.

After searching the car, the parking lot and the AG’s office, Highway Patrol found no sign of any explosives. It was about an hour between the initial call and the all-clear.

The threat disrupted ongoing grand jury proceedings, according to a report from Fox25.