In a bit of a strange situation...

Okay, so this story is quite long, so feel free to just read the Tl;Dr.Also, throwaway, for personal reasons.Okay, so the other month, I came out to my best friend, who we'll call Jake. He was awesome about it <3 Yay! He has a girlfriend (We'll call her Anna) who he told and she instantly wanted to start hooking me up with guys.So, this is awesome! Probably more than I could ask for at this point because just being accepted is enough for me haha.Anyway, so Anna messages me one day asking weather I was interested in a particular guy (Let's call him Tom)... I had met him before before we were both out and I had no idea that he was gay. She sent me pictures and stuff and I agreed to talk to him over Facebook.So I get talking and he is super cute like really really cute. He shares common interests with me and we are happily talking! It's his birthday when we were talking as well so that may have influenced some of the things that I said (Compliments etc.).So a few days pass and he doesn't respond to any of my messages... a bit odd but oh well. And that's when Jake calls. He calls me and tells me to delete Tom instantly and never talk to him again. A bit strange, so I ask him why.He then tells me that Tom had gone over to Anna's house, uninvited, and shoved his tongue down her throat. He fingered her, and really scared her. She ended up running and locking herself in the bathroom until he left, texting Jake about it.Tom then starts messaging me. But in a really casual way, you know? 'Hey man, how are you?', 'How was your day?'.So now, I start messaging Anna asking if she's okay. She repeats what Jake says about Tom and I comfort her.I meet up with Jake and Anna a few times after the incident and they just keep repeating their disgust and hatred for Tom.And now, a few months later, Tom has started messaging me again. In again, the casual kind of small talk.Anna has been recently expressing her sympathy for him, because he has been apologizing non stop since the incident.What should I do? Sorry for the ramble, I'm a bit tired at the moment... Thanks for the help guys <3Tl;Dr: Friend tries to set me up with a guy, who ends up sexually harassing and scaring her. He has started messaging me again.