Marines

 His once clean-shaven face was covered with a bushy beard. A short time later, four Marines lay dead. A sailor who was seriously injured died Saturday.

He was believed to have been born in Kuwait, and it was unclear whether he was a U.S. or Kuwaiti citizen. The official was speaking on condition of anonymity to discuss the ongoing, sensitive investigation. It was not immediately clear whether the gunman's first name was spelled Muhammad or Mohammad.