A portion of Newark Penn Station was shut down Saturday as New Jersey Transit Police simulated an active-shooter situation.

During the drill, police officers practiced their response to a fictitious disturbance on a lightrail train that had just pulled into the station.

Officers simulated shooting and killing two armed suspects who mimicked firing at them and arrested a third.

"Mass transportation is always a target, it's always a priority on any terrorist list," says Capt. Robert Noble. "The state of New Jersey, we always have the highest threat in the country so for us not to do this, we'd be remiss to not do this as often as we do."

NJ Transit puts its officers through active-shooter drills several times a year.