No you don't need to. It's better that you don't. It looks very cliche and well, fake if you just add a few sentences at the end of your essay. They will definitely be able to tell.For your reach schools I would recommend putting together a one-page Why Law addendum.
I'd love to join this LGBT club. It's the Legos, Gobots, Barbies, and other Toys group, right? I'll show up with an armful of toys.