Were red flags missed or unheeded that could have prevented the deadly rampage at Fort Hood, Texas?

While grieving Americans sift through information about the suspect, whose sworn duty had been to provide mental health care to his fellow soldiers, avid investigation will determine if military policies must be changed to guard against future attacks from within.

Maj. Nidal Malik Hasan, 39, an Army psychiatrist, was shot four times and was reported to be unconscious on a ventilator following the rampage that left at least 13 dead and 30 wounded. Hasan is reported to have used two “;civilian”; guns, including a semi-automatic.

At all military bases, service weapons are required to be checked daily at an arms room and allowed to be removed only for training on a firing range or for maintenance. Personal weapons are registered and locked with the base provost marshal. Hasan lived off-base and could have simply brought the two guns onto the installation.

He was described as a troubled soldier who was upset about his future deployment in Iraq or Afghanistan and wanted a discharge. Before opening fire, he was heard to shout, “;Allahu Akbar”; - Arabic for “;God is great.”;

Hasan was shown on a security video tape at a local convenience store wearing Islamic garb hours before the shooting, although he entered the base in uniform. He had listed “;no religious preference”; on his Army personnel records but had been open about being a Muslim, which by itself should be of no significance.

“;We always have a deep and enduring concern that everybody be treated with dignity and respect,”; Army spokesman Gen. Kevin Bergner told reporters.

The question is whether Hasan's religious beliefs had become so openly extreme in the context of wars against Islamic terrorism that they deserved notice - and stronger action.

Earlier this year, law-enforcement officials monitoring Islamic Web sites identified Hasan as a blogger who equated suicide bombings with acts by soldiers using their own bodies to shield fellow soldiers from shrapnel, asserting that both actions were “;for a noble cause.”;

Hasan reportedly required counseling at different times, but friends and relatives describe him as cordial and reclusive, outgoing only with his faith.

A Walter Reed Hospital psychiatrist told National Public Radio that Hasan, using a physicians academic forum while working at the Washington, D.C., hospital, lectured doctors that the Quran says a nonbeliever should be beheaded and have burning oil poured down the throat. A Muslim psychiatrist in the audience reportedly disagreed with Hasan's claim regarding Islamic scripture.

The Army's task will be to determine the veracity of such reports, the adequacy of the response and whether policy should and can be changed without infringing on the religious freedom of the troops.