Senate to press ahead with probe into Fort Hood

U.S. President Barack Obama speaks during the III Corps and Fort Hood Memorial Ceremony held to honor the victims of the shootings on the Fort Hood Army post in Fort Hood, Texas, November 10, 2009.

WASHINGTON (Reuters) - Two U.S. senators vowed on Wednesday not to interfere with a criminal probe of the Fort Hood shootings but said they must move ahead with their own hearing into the rampage.

Joe Lieberman, an independent who heads the Senate Homeland Security Committee, and the panel's top Republican, Susan Collins, want to know if the U.S. military and law enforcement agencies missed warning signs.

The two said they also wanted to determine if authorities shared relevant information before shots rang out at the Army base in Texas on November 5, leaving 13 dead, dozens wounded and an Army major, Nidal Malik Hasan, a Muslim born in the United States to immigrant parents, charged with the massacre.

The Obama administration has briefed lawmakers about the shootings and signaled them to tread carefully in any inquiries of their own because it does not want to compromise criminal investigations by the FBI and Army.

Lieberman's committee plans on Thursday to hold its first of likely several hearings on the shootings.

"I support those investigations, look forward to their outcomes, and have no intention of interfering with them," Lieberman, flanked by Collins, told a news conference.

"But that does not mean that the rest of us, including the Senate Committee on Homeland Security, can just sit back and watch," Lieberman said.

The senator said his committee had a responsibility "to determine whether the federal government could have prevented the murders at Fort Hood."

Hasan had sent e-mails last year and this year to a radical Muslim cleric in Yemen, U.S. officials have said. Intelligence agencies discovered the messages, but joint terrorism task forces determined they did not warrant further action.

The New York Times quoted an unidentified congressional official on Wednesday as saying the messages "were not overtly aggressive," but "should have raised flags."

Lieberman said that based on information publicly available, he believed the shootings amounted to "the most destructive terrorist attack on America since September 11, 2001."

U.S. Attorney General Eric Holder, testifying before the Senate Judiciary Committee on Wednesday, said President Barack Obama had given federal authorities until the end of the month to come up with some findings from their investigation.

"That's an indication of how serious we take this and how quickly we want to get to the bottom of it," Holder said.

(Additional reporting by Steve Holland and Jeremy Pelofsky; Editing by Peter Cooney)