No, there really isn't. The fact a department can investigate themselves is like if each individual McDonald's franchise hired their own health inspectors.

This is a state-dependent observation, and isn't true in many departments. Different levels of investigation occur depending on the circumstances and facts of a complaint or issue. Blanket statements like this show a rather glaring lack of knowledge on the subject.

The police need to be held accountable to the public, on all public complaints. If you accidentally kill someone, you will be charged with manslaughter. It's that simple. No one is above the law.

The law is the law. Every crime has a defined actus and mens, and these elements are further clarified in copious volumes of case law. The fact of the matter is that accidental killings do not generally satisfy the requirements for a crime in most states.

Again, your lack of actual knowledge on the subject is somewhat glaring.

Secondly, their needs to be an annual fitness test for LEOs. So many LEOs use their guns because they can't defend themselves physically, and therefore fear for their lives. This is perfectly reasonable, however, their unwillingness to stay in shape has a negative affect on the public.

You make quite a few blanket statements here, and provide nothing to back them up. "So many" use their firearms because they cannot defend themselves? The evidence you provide is a video of an officer who was attacked by a mentally disturbed man. The unprovoked attack broke his arm and his foot.

I realize that you are, in fact, an internet badass, but please educate the rest of us: how do you intend to defend your life with a broken arm and foot? Do you know some sort of deep-jungle Balinese martial art that allows you to ignore the searing pain from several broken bones and the disability that prevents the use of an arm, as well as a leg?

You are the reason that none of take internet commenters seriously.