My co-worker is trying to sabotage me!! Should I go to HR with this problem?

I need to know if I go to HR!!

I have been working at my company for close to two years. I have mastered everything that has come my way and have a pretty good reputation with the higher ups'. I have also been told I have promotion waiting for me at the end of summer after I graduate. Here is the drama.... A new girl started about 2-3 months ago and she shares my office after I leave for the day. First, she was really messy, then started to throw my notes away, go through my drawers and remove my things and put her stuff in it's place. (this is my office and my boss allows her to be there only when I am gone) She even has gone into my personal voicemail and erased messages from my saved box that were for me only. These messages were needed the next day for me to return important calls. All gone. I went to my Director and explained what has happened so far. So I took it upon myself to be the mature person and approach the girl and let her know we are here to work together as a team, so lets just start with a clean slate. She agreed. Well, here is the issue that is so messed up!! A different co-worker came up to me today and informed me that when she walked in on this girl the other day, this girl had pulled up my old arrest record from over 12 years ago. She was looking at my picture (plus she was in her managers office doing this) and sharing it with the co-worker that told me about this. It was my arrest record, and I have never been convicted. I was arrested for something stupid but never charged. My company did a background check on me when I first began. I also brought the record to my Director and H.R. in the first week I began so I would not hide anything or have it bite me in the butt later. I can not tell you how pissed off I am. What else is this girl going to do to me? This girl also has been caught by me trying to lie on her timesheet and try to increase her pay by 3 hours. There is something very wrong about this girl. If she is so negative and hateful towards me for no reason, well, this makes me so uncomfortable.. Is this a valid reason to go back to my Director and HR??? (I don't want to look like a narc, but this is pretty personal.) Please I need urgent advice. Please help, what would you do and who should I talk to?? I want to be as professional as I can be. Thank you all for your time!

One other thing, the arrest record is public record in the state of Florida. So is this still a violation of some kind because this happened in the work place??