Thirty-five years ago, Mark David Chapman shot and killed John Lennon.

The former Beatle was felled with Charter Arms .38-caliber pistol that the 25-year-old Chapman purchased legally in Hawaii. He hid it in his luggage.

At that time, baggage wasn't screened like it is today. Air travelers are still able to take a gun with them on a flight as long as they declare the weapon, unload it, lock in a hard case and check it in their luggage. Security experts say there's nothing to prevent someone who follows proper security procedures from collecting the firearm from the baggage carousel at the destination airport, even if the weapon is illegal to possess in the jurisdiction to which they have traveled.

Chapman pleaded guilty and is serving 20-years to life in prison. He was denied parole last year.