Unassuming on the surface, but roiling within

Army Maj. Nidal M. Hasan's anger was building.

He felt stuck in the Army, and family members said the military wouldn't let him out.

He disagreed with American policy in Iraq and Afghanistan, telling colleagues that the war against terror was a war against Muslims and that his religion came first.

He was a stranger to those with whom he prayed daily.

And even those who liked Hasan and saw him every day viewed him as an odd recluse who was often standoffish. They didn't know him very well and are trying to understand how he could be the man authorities think shot dozens of people at Fort Hood in Texas on Thursday in a rampage that has left 13 dead.

Two days before the shootings, he calmly walked around his apartment complex in Killeen, Tex., giving away his possessions: the microwave, the clothes rack, the shirts and suits that were practically new. But the people getting his belongings said they hardly knew him, and he barely spoke as he doled out his things.

The owner of a halal restaurant near the Silver Spring mosque where he worshiped before his recent move to Fort Hood said he would come in alone and rarely got into extended conversations, even though he'd eat there a couple of times a week.

He wasn't nearly as reticent in sharing his political beliefs. Val Finnell, a classmate of Hasan's at the Uniformed Services University in Bethesda a few years ago, recalled a presentation that "started out with a semblance of a health issue but his PowerPoint turned into his view that the war was against Muslims. He brought that up throughout the year."

When he was challenged by others in the class, Finnell said, "he became emotionally upset."

Authorities said they were exploring whether Hasan was the author of an Internet posting that said suicide bombers were heroes with a noble cause.

A colleague at Walter Reed Army Medical Center, where Hasan was stationed for his psychiatry residency, said co-workers avoided referring patients to him.

His aunt said he was constantly berated for his Muslim beliefs and "must have snapped."