A report from the Department of Justice's Office of the Inspector General found that the U.S.'s various anti-terrorism agencies generally acted properly in handling and sharing information with each other regarding Boston Marathon bomber Tamerlan Tsarnaev after Russia warned the U.S. about him, but also failed to better vet him prior to the bombing.
"Based on all the information gathered during our coordinated review, we believe that the FBI, CIA, DHS, and NCTC generally shared information and followed procedures appropriately," the report concludes.
Three people were killed, and hundreds were wounded in twin blasts that exploded near the race's finish line on April 15, 2013.
Tamerlan Tsarnaev and his brother Dzhokhar Tsarnaev are accused of carrying out the bombing. Tamerlan Tsarnaev was killed three days later during a police manhunt. His brother, who has pleaded not guilty to numerous charges including murder, is in custody and due to go on trial in November.
The main shortcoming of the investigation, the report found, was in the FBI's failure to notify the CIA after it was first contacted by Russia's security agency in March 2011 with the information that Tamerlan Tsarnaev was an adherent of radical Islam and planned to travel to Russia to join underground groups in Chechnya and Dagestan.
Instead, the report said that the FBI-led Joint Terrorism Task Force in Boston (Boston-JTTF) conducted its own three-month assessment of Tsarnaev that found no connection to terrorism. After the assessment's conclusion, the FBI wrote two letters to Russia asking whether it had any additional information justifying suspicion of Tsarnaev. Russia did not respond to these letters prior to the bombings.
While the FBI erred in not contacting the CIA, the report says, the CIA's involvement was not likely to have added any additional information to the FBI's investigation and thus likely would not have prevented the bombings.
The FBI special agent assigned to Tamerlan's case, it notes, would have been justified in conducting a more thorough investigation of Tamerlan, but also was not negligent in failing to do so, as FBI procedures allow agents leeway in making such judgments.
The CIA only found out about Russia's allegations regarding Tamerlan six months later in September 2011, when they were also contacted by Russia. The agency then notified other groups such as the National Counterterrorism Center (NCTC), which led to Tamerlan being placed on a terror watchlist.
While restrained in its criticism of U.S. security agencies, the report does mention several pieces of valuable information that could have been found out before the bombings, but were not. For example, government agents never noticed a YouTube account created by Tamerlan which began posting jihad-related videos in October 2012, six months before the bombing.
Agents also failed to interview Tsarnaev's wife as well as a former girlfriend, who they say would have been available for interview in 2011 and potentially could have testified to his growing interest in radical Islam.
Lastly, despite being warned by Russia that Tsarnaev was planning to travel to Russia to join underground groups, the FBI's counterterrorism agent failed to make inquiries regarding such a trip, and when Tsarnaev made the trip in 2012 it failed to arouse FBI suspicion.
The report indicated disagreement within the FBI about whether Tsarnaev's trip to Russia should have aroused greater interest. The counterterrorism agent in charge of Tsarnaev's case said it was not a significant event because the FBI's investigation had already closed, while his supervisor argued that had he been notified of Tsarnaev's travel he likely would have reopened the investigation.
Despite the errors found, the report said none were important enough to justify "broad recommendations" for changes to how security agencies handle and share information. The only notable recommendation was that the FBI create procedures to be more proactive in notifying state and local authorities about individuals who are subjects of counterterrorism assessments.
Sen. Tom Carper (D-Del.), Senate Homeland Security Security Committee chairman, said he would hold a hearing with the report's authors and other government officials.
Carper said in a statement that the report "helps answer some of the critical questions about what could have been done differently, what worked well in our prevention and response efforts, and what more we can do."