Unclassified Summary of Information Handling and Sharing Prior to the April 15, 2013 Boston Marathon Bombings [open pdf - 5MB]
"As outlined in a May 21, 2013, memorandum from the participating Inspectors General, the objectives of this review were to determine:  The extent of the information available to the U.S. government concerning the relevant individuals and events preceding the Boston Marathon bombings;  Whether the sharing of this information was complete, accurate, and in compliance with U.S. counterterrorism and information sharing, policies, regulations, and U.S. laws; and  Whether there are weaknesses in protocols and procedures that impact the ability to detect potential threats to national security. In furtherance of these objectives, the Offices of Inspector General (OIGs) sought to develop a chronology of the events leading up to the bombings based on information that was known to the U.S. government prior to April 15, 2013. We also sought to identify what additional information existed and may have been available to the U.S. government before the bombings. In considering whether information that existed prior to the bombings was 'available' to the U.S. government, the OIGs took into account the limited facts known to U.S. government agencies prior to the bombings and the extent of the government's authority under prevailing legal standards to access that information. As a result, the scope of this review included not only information that was in the possession of the U.S. government prior to the bombings, but also information that existed during that time and that the federal government reasonably could have been expected to have known before the bombings."
U.S. Department of Justice: http://www.justice.gov/