HI, I'm Heather, an attorney of 15 years, and I'd like to assist you for informational purposes.
If you weren't gone for very long, and if you were paid up in rent, then the landlord should not have took this guy's word to believe that you'd moved out. From what you have described, you have a cause of action against the landlord for wrongful eviction.
Unfortunately, the claim against the con man will be a bit harder. The issue with the fight is your word against his, and obviously, the police believe him for the time being.
However, your landlord probably has a claim against the conman for fraud, because the conman lied to him or her to get a lease signed, and therefore, if your landlord is found to be liable for any damages for the wrongful eviction, they can file a cross claim against the conman to have the court hold him responsible.
Let me know if this has answered your question.