FILE - the FBI's J. Edgar Hoover headquarter building in Washington.
FILE - the FBI's J. Edgar Hoover headquarter building in Washington.

WASHINGTON - The FBI failed to significantly improve its handling of investigative tips and leads on suspected homegrown violent extremists even after several high-profile terror cases put the spotlight on the problem in recent years, according to a new report from the Justice Department’s inspector general.

The FBI describes homegrown violent extremists or HVEs as self-radicalized “global jihad-inspired individuals” who are living in the United States and not receiving direction from a foreign terror group. Since 2001, homegrown violent extremists have been responsible for 20 attacks in the United States, some of which came after the FBI closed an investigation on a suspect.

Following criticism that it had missed critical leads into terror suspects such as Pulse nightclub shooter Omar Mateen in Orlando in 2016 and bomber Ahmad Khan Rahimi in New York that same year, the FBI conducted an internal review of counter-terror assessments in 2017.  An assessment is an early investigative look at a case and precedes a preliminary and full probe.

Although the bureau’s review found that 6% of assessments that closed between 2012 and 2016 warranted additional action, not all of the FBI’s field offices carried out the necessary work, Inspector General Michael Horowitz wrote. “

As a result, nearly 40% of these counterterrorism assessments went unaddressed for 18 months after deficiencies were known,” the inspector general wrote.

The FBI has since taken corrective steps, according to the inspector general, leading to opening new assessments or investigations. The bureau has also agreed to implement all seven of the inspector general's recommendations.

The report highlights seven terror attacks whose perpetrators had been investigated by the FBI before being let go.

The FBI investigated Mateen for 10 months before determining that suspicions that he had terror ties were “unfounded.” In Rahimi’s case, the bureau closed its brief assessment after finding that “no nexus to terrorism could be found.”

Others that had been investigated by the FBI before carrying out terror attacks included Fort Hood shooter Nidal Hasan and Boston Marathon bombers Tamerlan and Dzhokhar Tsarnaev.  

Hasan, a U.S. army psychiatrist, killed 14 people and injured more than 30 others in 2009 the deadliest attack on an American military base.  In the 2013 Boston Marathon bombings, three people were killed and several hundred injured.