Collins says she wants to know why warning signs about the alleged shooter, U.S. Army Major Nidal Malik Hasan, went unheeded.

Maine Sen. Susan Collins says it's apparent that the nation's intelligence sharing efforts remain inadequate. Collins made the remark at a hearing by the Senate's Homeland Security and Governmental Affairs Committee on the Fort Hood shootings, which killed 13 people at the Texas military base.

The hearing opened yesterday, and Collins, the ranking Republican on the committee, said despite all the efforts since 9-11, serious shortcomings in the nation's intelligence sharing system linger. She said it appears that information about the alleged shooter that might have prevented the attacks was not shared, according to Capitol News Service.

"That is our challenge, as we learn more through our investigation, to identify legal barriers, administrative impediments, that may have blocked the sharing of information in this case," Collins said.

Collins says there will be more hearings in Congress in the months ahead, looking at how law enforcement, intelligence agencies and the military share information and what barriers remain. U.S. Army Major Nidal Malik Hasan is charged with the killings. Red flags had been raised about Hasan, a military psychiatrist, prior to the shootings, and Collins says she wants to know why those warning signs were not heeded.