FORT HOOD, Texas -- As if going off to war, Maj. Nidal Malik Hasan cleaned out his apartment, gave leftover frozen broccoli to one neighbor and called another to thank him for his friendship -- common courtesies and routines of the departing soldier. Instead, authorities say, he went on the killing rampage that left 13 people at Fort Hood, Texas, dead.

Investigators examined Hasan's computer, his home and his garbage yesterday to learn what motivated the suspect, who lay in a coma after he was shot four times.

Hospital officials said some of the wounded had extremely serious injuries and might not survive.

The 39-year-old Army psychiatrist emerged as a study in contradictions: a polite man who stewed with discontent, a counselor who needed to be counseled himself, a professional healer now suspected of cutting down the fellow soldiers he was sworn to help.

Relatives said he felt harassed because of his Muslim faith but did not embrace extremism.