Four people, including the gunman, were killed and eight others were injured in a shooting at Naval Air Station Pensacola. CBS News has learned the gunman was Mohammed Saeed Alshamrani, a Saudi Arabian national, and a pilot-in-training for the Saudi Air Force. He had been training in the United States since 2017. The FBI is investigating the suspect’s social media posts and whether he acted alone. But investigators have not said what his possible motive might have been. David Begnaud reports.