A report emerged just days before the Boston bombing that the finish line of the Boston Marathon could be an easy target for potential small-scale terrorist attacks. The 18-page report was disseminated through the ranks of the local police before the marathon.
The police complained at a hearing that they needed to know more about the potential suspect, essentially pushing any blame towards the FBI, who interviewed Tamerlan Tsarnaev when he was flagged by Russia for possible ties to extremism.
As it turns out, their concerns were justified, but not enough to raise any more concerns. It may have been impossible for the FBI to know how far down the path Tsarnaev was heading at the time, and the reality is that these attackers are often impossible to predict despite signs that seem obvious after the fact. All of the recent school shootings seem to involve issues with parenting or community or video games, but none of them were prevented.
The simple fact is that reports like these from the FBI must be taken seriously immediately by local police forces and other federal agencies whose job is to protect American citizens. Communication is essential, as the government should have learned in the wake of September 11th.