The suspect detained after a shooting at the White House Correspondents' Association dinner is believed to have made it past the outermost layer of security at the event at which President Donald Trump was scheduled to speak because he was a guest of the hotel, officials said Saturday. Security for the annual event is always tight when the president attends, especially given the venue’s history — 45 years ago, the Washington Hilton was the site of an attempted assassination of President Ronald Reagan — and law enforcement argued that their “multi-layered protection” worked as designed. Still, the incident was sure to set off more questions about security around the president and political events in the wake of high-profile acts of political violence in recent years. Here's what we know about the security of the correspondents' dinner.…