The other night my girlfriend and I were out with one of our coworkers. While I was absent he stole her phone, guessed her passcode, and went through her photos without her consent (there were nudes) as well as refused to give her phone back. I was not present for the incident, I heard about it after the fact and because she didn’t want to cause a scene and because the offending party was shitface drunk we did nothing about it at the time. When our boyfriend learned about it he was totally furious. We want to make the guy pay for what he did. However, my girlfriend and I both work with him and we are both new on the job (food and bev) and reluctant about what to do since we don’t want to start drama.

What should we do? If I wanted to I could probably get him fired but if at all possible I’d like to leave my workplace out of it.

It should have been reported to the police when it happened. At this point, it's probably best you keep an eye on him, and if he does anything too suspicious, to call someone who can deal with it.