In the arrest one, you should mention how long ago this occurred and what you learned from the situation, that you know it was wrong, you've changed, etc. Unless you are still soliciting prostitutes, in which case you should write about that and how it has affected your choice to attend law school. I hear that Stanford has some grads who are pursuing the sex industry, maybe you should apply there.
In all seriousness, I have a feeling that unless you can demonstrate that you are a totally different person and what you learned from the situation, this will negatively impact your application. I highly doubt that female ad-comms would be that impressed by your past actions, I know I sure as hell wouldn't be. Give it some careful attention, and good luck.