The FBI released video today of Aaron Alexis, gun in tow, at the Washington Navy Yard prior to the shooting that left a dozen people dead:

https://twitter.com/Matthops82/status/382926867453329408

Absolutely frightening.

https://twitter.com/ndiblasio/status/382929024013451264

The video becomes even more terrifying when you think about what happened next.

https://twitter.com/BrentinOcker/status/382928143046443008