SE’s Story: Groped while getting onto the bus

I was waiting to board my bus home after work – by the back door, because the Metro bus I take is notoriously busy (and gross, but that’s another story). I stepped slightly to the side, as I always do, so that others could de-board before I got on the bus. One man stepped off, and said an awkward, “hi” as he passed me. The next man, whom I’m assuming was with him, reached out and grabbed (rubbed, really) my breast as he walked past me. I was SO shocked, I continued to step onto the bus. I couldn’t believe that had just happened. I had a weird moment of disconnect, like I was just watching his hand come at me. I don’t know if anyone saw, but if they did, no one said anything. I was angry/totally freaked out/sad that I didn’t even SAY ANYTHING to him. I didn’t even get a good look at him, so I had no description. I called the police to report it, because I felt so terrible that he got away with it because I didn’t scream at him or react in any way. I was angry. The police couldn’t do anything, obviously, since I had zero description and it’d happened hours earlier, but I felt better having reported it so SOMEONE. Now, I cross my arms as I board the bus, and today boarded with my cell phone camera at the ready in case something similar happens again. This was a rude awakening that I need to be more alert, ready to use my voice, when downtown and on the bus.