I hate to say this, but do you know what he’s done to rehabilitate himself? Do you know why he’s allowed to work there? Have you talked to management about what you discovered?
All of your questions are very very leading. Of course we deplore rape. However, despite what you may think, we should all be given a chance to redeem ourselves.
I can understand why you fear for the safety of yourself and others around you. If you do nothing, that is entirely on you. But I do hope that you have compassion and a sense of forgiveness in your heart too. For all you know, you can also be surrounded by thieves and murderers, but none of those are publicly branded.
I urge you to bring this to the management’s attention. Talk to your female coworkers and let them know.