A senior military official says investigators probing the shooting spree that killed 16 Afghan civilians are looking into the possibility that alcohol played a role.
The official spoke on condition of anonymity because the investigation is under way.
The official says it's unclear whether the suspect had been drinking before disappearing from his military base in Kandahar province or whether alcohol was simply found in his living space at the base.
Military rules prohibit the use or possession of alcohol in a war zone.
The suspect is said to be a 38-year-old Army staff sergeant who was sent to Afghanistan in December. He had served three previous tours in Iraq.