Yes, a finding of police brutality against an officer should be grounds for immediate termination. Police officers are specifically charged with upholding the law by trade. For that reason, it is rather important that they are held to at least the same standards, if not higher, than civilians are subject to. They are public servants who get paid by the taxpayers dollar.
Yes, I think that once an investigation has concluded and the finding is positive, termination should be immediate and final. As in, no further chance to work in legitimate law enforcement ever again. Our police have become too corrupt. It's time to remind them they are here to serve and protect us, not terrorize us.
If there has been an investigation along with an official ruling and it is found that a police officer has brutalized someone he was arresting (and it is usually a man who does this), then that police officer should be let go from his job immediately and he should not get full benefits of any sort.
If a police officer is charged with police brutality he or she should be terminated immediately. I do think there are cases where this shouldn't be, such as when cops pummel a serial killer when they catch him, but in most cases, yes; terminate the cop for excessive police force.
While I do not support brutality, the officer in question should be allowed to tell his side of the story. These are circumstances behind this that we may not know of. It is unfair to assume the officer is at fault and immediately terminate them. They should be temporarily suspended, but not terminated.