According to CNN: “[F]ederal law enforcement sources told CNN Tuesday that authorities have recovered three weapons from the scene of the mass shooting, including one – a shotgun – that investigators believe [Aaron] Alexis brought in to the compound. The other two weapons, which sources say were handguns, may have been taken from guards at the Navy complex.”

Eventually, somebody was going to figure this out. You don’t need to carry a firearm into a secure government building in order to kill lots of innocent people. You only need the the ability to use any of hundreds of methods to disable somebody on the inside of that facility, and take his or her weapon.