Americans continue to wonder whether the terrorist rampage at Fort Hood could have been prevented.
What did government agencies know about Nidal Malik Hasan, and when did they know it? And how deep were Hasan's jihadist connections overseas?
In this post-9/11 world, it seems hard to believe. Details are emerging that U.S. government agencies knew about Hasan's contacts with Islamic radicals linked to al Qaeda -- and concluded that those contacts did not pose a threat to America's national security.
Click play to watch Erick Stakelbeck's report followed by comments fro Pat Robertson.
Also, Hasan's radical religious beliefs have raised questions about other Muslims in the military. Retired Maj. Gen. Robert Dees told CBN News there's a reason the issue has been ignored. Click here for his comments.
For months, federal investigators monitored Hasan's e-mail correspondence with Anwar al-Awalki, an al Qaeda recruiter living in Yemen who has been linked to three of the 9/11 hijackers.
"Awlaki is known as a senior recruiter for al Qaeda. He clearly has the ability to convince people to kill others and perhaps even kill themselves," former FBI agent Brad Garrett said.
The FBI passed information about Hasan's contact with al-Awalki to a terrorism investigator at the Department of Defense.
The investigator's verdict? Hasan had contacted al-Awalki as part of a research paper he was working on about the effects of combat on U.S. soldiers in Iraq and Afghanistan. Therefore, he did not merit any further attention.
The details came as the nation remembered Hasan's victims at a memorial service Tuesday.
"No faith justifies these murderous and craven acts; no just and loving God looks upon them with favor," President Barack Obama said.
But those on a growing list of homegrown Islamic jihadists disagree. Seven terrorist plots have been foiled by the FBI on U.S. soil in the last six months alone.
Several others have been arrested or are under investigation for providing support to terrorists and related activities.
One plot was successful. In Arkansas, like the Fort Hood attack, the military was the target when an Islamic jihadist shot and killed an Army recruiter last May.
A senior government official told ABC News that Hasan had connections to several Islamic radicals in addition to Anwar al-Awalaki. Those connections will likely be made public soon, as lawmakers are planning a full investigation.