U.S.-born cleric Anwar al-Awlaki was killed in an airstrike in Yemen in August. He was the key spokesman and ideologue for al-Qaida in the Arabian Peninsula and was accused of being the ideological mind behind the Fort Hood attack, allegedly carried out by U.S. Army Maj. Nidal Malik Hasan.
A report by former FBI Director William Webster said there were a series of mistakes made in evaluating Hasan's discussions with Awlaki.
U.S. Rep. Peter King, R-N.Y., chairman of the House Committee on Homeland Security, said the report uncovered "serious lapses" in the way the FBI monitored Hasan before the attack.
"The report is a stark reminder that the domestic radicalization by al-Qaida and its affiliates is a serious threat to the homeland that absolutely must be addressed head-on by the federal government without concern for political correctness," he said in a statement.
Counter-terrorism officials testified last year that potential domestic attacks were "persistent" threats now that many of al-Qaida's leaders overseas have been either captured or killed.
Terrorism was ruled out in a deadly shooting Friday at a cinema in Colorado.