M.O.: find a patsy/patsies, lead them into an entrapment and make sure they have everything they need, most especially the license to roam free away from the prying eyes of honest agents who would blow the whistle and stop it in its tracks. Now think: at the last minute they have bomb dogs frantically working the finish line and they are announcing to people not to worry. Part of a cover drill? Maybe. Also perhaps someone on the inside gets a tip-off or senses something wrong, and jumps the chain of command in an honest last minute attempt to avert.
Mueller should be tied down and waterboarded to find out why he didn't have Tsarnaev tailed 24/7, and "I forgot" won't be good enough.
Release the Sandy Hook video.