I think an expert should weigh in but that neatly formed powder burst to the right of the blood pool surely didn’t come from anyone else but HIS weapon. The DIRECTION of the burst appears to be TOWARDS HIS HEAD and not AWAY FROM HIM, too.
Look at that perfect round hole on his left eyebrow ridge
The photo of the dead shooter suggests someone moved the head(and body) because the blood trail is flowing up on the face. It also appears the deceased’s teeth are missing which is an interesting anomaly. Furthermore, an interview of a trauma physician elsewhere in this post pointed out that a head shot with a high powered round from a distance would explode the head spreading blood and debris over several feet which is not visible on the white roof surface. The absence of teeth would suggest the deceased killed himself with a round in the mouth but there is no handgun present. Did he do it with the AR which might explain why the weapon is distant from the body or was the weapon moved by LE as a safety precaution? We need a legitimate autopsy to be performed.