WASHINGTON – A US Senate panel vowed to investigate the circumstances surrounding the Nov. 5 murders at Fort Hood, opening public hearings on Thursday and invoking a broader discussion on homegrown Islamic extremism, political correctness and whether intelligence agencies still fail to “connect the dots.”

“There were warning signs and red flags galore,” said Sen. Susan Collins (R-ME), the ranking member on Senate Homeland Security and Governmental Affairs Committee, referring to the Fort Hood tragedy. “When you start to put together all of the pieces of information, it reminds me very much of the siloed information that was available throughout the federal agencies prior to the attacks on our country on 9/11.”

Members of the Committee also wondered if suspect Major Nidal Hasan, an Army psychiatrist charged with killing 13 fellow service members in the murderous rampage, acted as a “lone wolf,” and if so, what law enforcement tools are at their disposal to ensure “self-radicalized” Americans don’t pose a similar threat in the future.

The White House had hoped Congress would hold off on hearings until the official criminal investigation had time to run its course. As a result, it did not provide administration officials to testify Thursday, limiting the panel’s scope and the detail of the discussions.

Lieberman bemoaned the lack of full cooperation, but said committee members were given a classified briefing before Thursday’s proceedings.

“[Secretary of Defense Robert Gates and Attorney General Eric Holder] said they respect our authority to conduct an investigation,” said Lieberman. “I assured them our committee understood and respected the difference between their criminal investigation and our congressional investigation. Their investigation looks backward and is punitive and ours looks forward and is preventative ... we are off to a good cooperative start.”

Hasan, who is still in critical condition after being shot by a police officer after the shootings, is a Muslim-American of Jordanian descent, according to reports. Lieberman said his investigation will focus on the threat of “self-radicalization,” pointing to Hasan’s seeming personal journey towards Islamic extremism. “We will look at the Fort Hood murders not as an isolated event, but as part of a larger pattern of homegrown terrorism that has emerged over the past several years” he said in his opening statement.

Meanwhile, the DoD launched its own formal inquiry on Thursday, with Secretary Gates naming two former commanders to head a 45-day investigation into the system’s “gaps and deficiencies” that could leave U.S military personnel vulnerable to future attacks.

“I am optimistic that we will work out a way for both investigations to proceed without compromising either,” said Lieberman.

So instead of administration officials, Lieberman and Collins tapped experts in military, law enforcement and counterterrorism to inform the committee on Thursday. Not all of them were willing to readily claim the Fort Hood homicides were a domestic act of terrorism. For now, that official designation appears up for debate, as is who might have dropped the ball in the months and days leading up to the killings.

Intelligence sources have told reporters in recent days that since last December, they were aware of Hasan’s email communications with fundamentalist Imam Anwar al-Awlaki, who now resides in Yemen and has reported ties to al Qaeda. They did not pursue an investigation because the communiqués were understood to be part of “research” Hasan was performing as part of his work at Walter Reed Army Medical Hospital, The New York Times reported on Nov. 9.

“The assessment by the JTTF (Joint Terrorism Task Force), they viewed it as a close call,” said former Bush Homeland Security official Frances Townsend, who testified Thursday. “I think over time, as more information comes, this committee will be able to judge whether that was the right judgment.”

Also testifying was Gen. Jack Keane, former Army Vice Chief of Staff, who was a commander at Ft. Bragg, North Carolina in 1996, when a pair of racially motivated murders rocked the base and prompted a full review of the Army’s anti-extremist policies. An investigation found that skinheads and neo-Nazis had infiltrated the ranks. In the end, Keane recalled, 21 soldiers were kicked out of the service. New regulations now specifically address racially motivated behavior, he said. “We will find that our policies will need revision again, to account for specific behaviors and attitudes expressed by Islamic extremists,” he said.

Other witnesses included Mitchell Silber, director of intelligence services for the New York City Police Department; Juan Carlos Zarate, a former Bush counterterrorism official and Brian Michael Jenkins, a senior advisor with the RAND Corporation.

Lieberman, Collins and Sen. John McCain,(R-AZ.), also a member of the committee, repeatedly enjoined the witnesses to talk about political correctness, and whether authorities hesitated in pursuing Hasan prior to the shootings for fear they would be accused of discriminating against a Muslim minority.

“I have talked to military officers who have stated that, at least up to now, a reluctance to pursue these things because of political correctness,” said McCain.

Others were afraid to jump to that conclusion. “I think his status as a medical doctor, his rank … may have effected the judgment of the FBI more than his ethnicity,” said Zarate.

Lieberman said the investigation will now center on fact-finding, but promised it will conclude in a final report and recommendations.

Kelley Vlahos is a Washington correspondent and regular contributor to HSToday.us.