Definitely you could notify HR. The problem is that most of the times, if you inform HR of anything, it will backfire on you. And, most likely cause you more harm than what you would think.
If you are at-will you could be dismissed for complaining. I would suggest that you get some information, guidance on how to handle the issue through a professional. An attorney will be able to guide you through the situation.
Good Luck.
Totally depends on specific company policy.