He's certainly mentally ill. I'd have to be in the same room to tell if he was possessed or not. If he is already incarcerated -- the demon won't stay with him because its ability to interact in the world would be diminished. It would move on to a host out of prison where it could directly affect the world.

As far as this video goes -- it depends when it was filmed. If it was immediately after the incident then it is possible that a demon (if present) was gleefully rejoicing at the havoc it inspired. I could not tell unless I was in the room with that guy.

When demons "move" (in or out of a space or person) -- how can I put this? Something goes off with time. And there is a a burst of something in the air. I won't use the term "energy" because it upsets scientists -- they have specific meanings for terms. But it feels like getting hit with something even though there is nothing there and it sort of rolls over the room.

My experience with this type of thing dates back many decades. And it was not the result of anything which, I did. Rather -- something someone else got involved in and tried to drag me into unawares. I received a crash course on spiritual protection and survived the encounter.