I wouldn't consider him a loose cannon. I would just say that he is politically active. I don't think his decision in reference to Obama was very smart, but you cannot dispute that he is politically active. He was a blogger and an active duty soldier doing what he thought was best. I can't blame him for going after a school board on a blog. Look at the things that are happening in school today, the things being taught.
You have it right. There was no history for the police to go on. Even if they had his history, that, in and of itself, is not a reason to disarm an American Citizen!
The natural state of man, the way G‑d created us, is to be happy.
Look at children and you will see