Many martial arts, including most forms of jujitsu, have applicability to law enforcement. However, there's a big caveat... To reach a street effective level in most of them takes dedicated practice and time. The handful of techniques selected in most Police Defensive Tactics programs that I've either reviewed or been taught are kind of generic, and direct. That's not surprising; there's just too much to be taught in the short time of the academy. I strongly encourage you to commit to some martial art program, especially one that's NOT aimed primarily at sports. Unfortunately, most commercial schools cater to kids and hobbyists, not those who'll need to use it regularly and for real.
But there are really plenty of threads on these topics; use the search function, especially in the General Self Defense section.
Take a look at the dojo; see what you think. Is it something that you'll do and continue to do? Do the instructors seem knowledgable and interested in teaching? Who actually teaches the newer students? In many cases, you'll find that it's senior students, not the "name" that owns the dojo. This isn't automatically a bad thing, it's just something to be aware of. It doesn't take a master instructor to teach a newbie... And... is it located somewhere that you'll actually go, regularly, and can you afford it? (These last two are actually major drivers, really... because if you won't go, or can't pay, there's no point in sweating the rest of it!)