If you use that baton, or even if you are seen with it by the wrong person, there is a good chance that you will be charged with a crime. Look up penal codes 12020 and 22210, possession of a club or baton in California is not legal.
(To say nothing of the desirability of such a law - just as a FYI)
(To say nothing of the desirability of such a law - just as a FYI)