I have no personal experience in the business of false flag terrorism, but I imagine that engineering a successfully staged terror attack to be blamed on innocent or semi-innocent parties with the goal of psychologically manipulating a population requires that one also be an accomplished storyteller. It demands an avid imagination and an organized sense of foresight. And, most of all, it requires a consistency of narrative. Without consistency, the audience's ability to suspend its disbelief is damaged, and they become disconnected from the fantasy being portrayed.
If I were the "writer" behind the "story" of the Boston Marathon Bombing, I would consider my efforts an abject failure.
The narrative of the event has changed multiple times in only a few days, following a hailstorm of conflicting observations from the government and the establishment-run media. The "villain" of the original plotline was clearly meant to be "rightwing extremism" as numerous mainstream talking heads, led by federal agency inferences, began repeating the "homegrown right wing terrorist" meme everywhere. This meme was partly abandoned after the alternative media and the Liberty Movement began its own investigation, revealing a large federal presence on the scene, including military Civil Support Teams often tied to the DHS and NORTHCOM, as well as the witnesses who observed what on-scene officials called "training exercises" during the marathon. I have no doubt that these citizen investigations forced the establishment to change the direction of their crime tale, and use Plan B patsies instead. This, however, complicated the momentum of the fiction, and created even more questions.
Comment: All paving the way for another spree of mass killing by the U.S. in the name of saving lives.