 He worked at a nursing center, was a member of a gun club, and the FBI thinks he acted alone. But the investigation is ongoing, and all of this happened on the eve of the Republican National Convention, which begins today in Milwaukee, and no doubt security procedures are going to be a key focus. I'm Matt Piper in Milwaukee. Officials here saying security is as tight as possible ahead of this week's events. President Biden says he has spoken to agency heads. I've directed the head of the Secret Service