I rented out a room in my flat to a male lodger in his twenties who seemed quite normal to start with (obviously). His first day/night passed uneventfully and I went away for the weekend. When I came back late on Sunday evening, he was very worked up and rushed to meet me, saying "Oh thank goodness you're back, I need some advice. My former landlord is threatening to kill me". He then went on at some length, very agitated and worked up, and being tired, I told him I couldn't deal with it there and then and needed to sleep for work tomorrow.
I went to my bedroom but some sixth sense told me to put something heavy in front of my door. I heard him trying the door handle in the night. Troubled, I went to work the next day wondering what to do about him. That evening was pretty much the same as the previous, and I resolved to ask him to leave.
The following evening, I told him that the flatshare wasn't working out and asked him to leave, although he could have a months' notice if he really needed it. I should point out that he hadn't even signed the lease at this point, as he had some reason for not transferring the deposit and first months' rent into my account, and I was holding off until he did that.
Anyway, he really kicked off and told me that I couldn't do that, he had tenants' rights, etc.. I told him I could, because he was a lodger. He then phoned his friend, a thuggish looking 6 feet 2 heavily built bloke who came and stood menacingly in my living room, not saying much, refusing to leave. So I had these two men in my flat that I was really uncomfortable with.
By this point, I was really sympathising with his previous landlord!
Anyway, I called the police, who really were excellent. They warned the thuggish friend to disappear unless he wanted to be arrested, had a stern word with the lodger and told him that as he hadn't signed the lease, he would have to leave that night, and that he better phone someone to stay with. They obviously believed that I was in danger. They told him once he had arranged to pick up his belongings, he had to contact them first and they would accompany him. This is what happened a few days later - he was accompanied by the police while he emptied his room and fully moved out. They really were excellent.
It doesn't end there! His MOTHER phoned me a few days later, begging me to reconsider as he "was a really nice boy really and upset at the misunderstanding".