Did he break the law with my daughter

My daughter K is 24 and has Aspergers abs severe anxiety. 4 months ago she got talking to a guy online who I will call S, within 2 weeks she had met him and within 4 she was going to his house 150 miles away from me. She had told him about her issues and he seemed fine about it. 
On Oct 26 she went to stay with him “for a month” she seemed happy there, she would call me most days and tell me they were talking about moving in together, I felt it was too soon but she wouldn’t be told. She stayed with him for Xmas and New Year. 

two weeks ago again, he was talking to her about her moving her things up there to live with him. On 15 Jan they went out, as they always did, laughing and went home and, as always he slept with her (not forced, she consented) When they woke up last Saturday morning, he basically told her he didn’t want her anymore, and she was to come home. His excuse is ‘I changed my mind, people can do that’ What this fast? I had to drive up there and get her, goes without saying she was, and still is a complete mess.

She spent the first half of this week bombarding him, trying to “make it work” his response? “I don’t think the relationship can work, I don’t want to be friends but I want to stay in contact” I eventually told him to block her on everything and stay away from her, that took him a couple of days but he’s finally done it. 
She honestly thought he loved her, she was planning a life with him and then he does that. She’s not eating, she just sleeps and dozes, she only comes out of her room for a drink and to use the bathroom. 

My question is, has he broken the law in anyway? From where I’m sitting he realised she was easy prey and vulnerable, he’s used her for what he wanted, and now he’s bored he’s dropped her like a hot potato. 

Also any advice on how to deal with her? My husband also has Aspergers so they don’t really ‘get’ each other, so it’s all down to me. I literally have her on suicide watch, she is so bad. Any advice would be gratefully received, I’m on my own with this and I can’t bare to see her in so much pain 

Thank you in advance