Sen. Joseph Lieberman, Ind-Conn., chairman of the Senate's Committee on Homeland Security and Governmental Affairs, told "Fox News Sunday" that his committee will press ahead with a probe of the shooting, in which 13 people were killed.
Lieberman said the motives of the suspect, Army Maj. Nidal Hasan, would be examined and that the committee would probe if possible ties to "Islamist extremism" were missed by police investigators.
"It's premature to reach conclusions about what motivated Hasan," Lieberman told Fox News. "But it's clear that he was, one, under personal stress and, two, if the reports that we're receiving of various statements he made, acts he took, are valid, he had turned to Islamist extremism."
Lieberman said his committee would work in conjunction with the FBI, adding that if terror connections exist, it would make the Fort Hood shootings the most serious act of terrorism in the United States since the attacks of Sept. 11, 2001.
Notable deaths of 2014 [PHOTOS]