In a closet, near the washer and dryer and wads of Hasan’s clothing, including fatigues, was a box of pill bottles. The medications included a 2001 prescription for Combivir, a drug often prescribed for doctors who may have come in contact with HIV, as well as the antibiotic Clarithromycin, a cough reliever and an antihistamine.

On a card table in the kitchen were coins from various countries, including Israel, and an empty package for a LaserMax gun sight, with a $229.99 pricetag. There was also a book about Islamic dream interpretation, “Dreams and Interpretations,” by Allamah Muhammad Bin Sireen. Anwar al Awlaki, the radical cleric in Yemen to whom Hasan had sent e-mails, has produced a lecture series on dream interpretation.