Are there any lawyers that will take a civil case concerning police brutality, if not located in the same state where the incident occurred?

Typically lawyers try to practice/handle cases in their geographic area so as to minimize travel expenses for the client and so as to be able to handle multiple cases. That being said there are many lawyers, that for the right case, will travel to other states to handle same. You should do an internet/web search for lawyers that regularly handle police brutality cases, and expand your search to other states, then call some of them and see if they will work on your case.

Probably, however it is somewhat inconvenient to handle a case in another state.

Handling a case out of state can get very expensive. Are you sure you can afford it? you sure you can prove it. all the police will swear it aint so, that you were assaulting an officer, that you resisted arrest etc etc etc ad nauseum.

The attorney has to be admitted in the state where the incident occurred, because the action will have to be brought in that state. Many lawyers, particularly those located close to a state border-line, are admitted in more than one state.