Bad Rent Experence with an indian guy__helps needed from our Chi

I have a house on the market. Meanwhile, I tried to rent it to cover some utility. Last weekend, I found an Indian guy from website, who relocated to my city for a new job. His wife accompanied him on the way. I only want to rent my house to single, as the house is still on the market, and may be sold out someday, and we do not want too many people living there affects the house showing issues. This Indian guy said his wife will only live here for a couple of days, and then come back another state. Also, he had nowhere to live on that day, but staying in hotel. On his promise living only himself, I also want to save his money and agreed to let him live there. I gave him the lock box number, and he took the key out and got into the house. At that time, I even did not know his more information. Sound like silly, but it happened. Then the nightmare is coming. This guy brought his WHOLE family to the house, including his 2-year-old daughter, his wife, and his wife’s two parents. They occupied most space with their belonging, and messed up the whole house. It will be impossible to sell this house if things like this. As he lied to us, and broke our agreement no more people stay without our permission, we decided to ask his whole family, including himself, to move out today. However, this guy refused to do so, and said he did not care us to call police even. It sounds like a hooligan! We called the police last night. However, this guy pretended to be a very pity guy and lied a lot to the policeman. The police officers said they could do nothing at this point, and we just can’t move them out without their agreement!! What a world this is! The police said we can’t evict them, and the only way to so is via court. You know, this will take long long time, and this guy knows this clearly, he said he is waiting for the court call. We are really so frustrated, our kind helps to him turn out into his hooligan behavior, and we can do nothing?! One last thing, we never get any money from him, no deposit, no rent… we don’t have any paper lease with him, just oral agreement.
I know I’m the silliest person in the world, please no criticizing, I would highly appreciate if our Chinese folk may offer any helps!
Thanks so so much!