that are leading to more questions at every turn. >> this image of air force one leaving las vegas flying behind the mandalay bay hotel. >> bump stocks like this, they use the recoil of the rifle to help pull the trigger much faster. it's almost like a machine gun. >> i've never heard of bump stocks until this tragedy. so i have no problem banning those. >> ban manufacturing or possession of accessories that accelerate a semiautomatic rifle's rate of fire. >> normally anything connected to gun control is a lost cause in congress, but this time several republicans say they are willing to consider this one. >> they've never even heard of the device before. and they're in congress. so many of them are open to a conversation. >> yeah, there are going to be some hearings. >> does america fromhave a gun violence problem? >> we're not going to talk about that today. >> we begin this hour with breaking news. multiple senior law enforcement officials tell nbc news stephen