The investigation into the Nov. 5. Ft. Hood shootings, which left 13 people dead, will be front and center at a Senate Homeland Security Committee hearing Thursday.
Senators Joe Lieberman, I-Conn., and Susan Collins, R-Maine, said they will work together with the White House on the investigation.
"We appreciate that the Army and the Justice Department are conducting a criminal investigation of this shooting," Lieberman, chairman of the 17-member panel, said. "But that does not mean that the rest of us, including the Senate Committee on Homeland Security, can just sit back and watch."
The committee will be investigating the threat of homegrown terrorism and whether the recent Ft. Hood massacre was the result of failures in intelligence.
Suspected shooter Army Maj. Nadal Malik Hasan has been charged with 13 counts of murder and could face the death penalty.
"If Hasan was showing signs, saying to people that he had become an Islamic extremist, the U.S. Army has to have zero tolerance," Lieberman told Fox News. "He should have been gone."
Both Lieberman and Collins said their probe will not interfere with other ongoing investigations.
The committee had planned to meet earlier this week, but Fox News reports it was postponed at the Obama administration's request.