Scary applicant: Should I just cut contact with him?

[Aaron K.]

This is about a person who has applied to rent a house. He is charismatic and likeable, talkative and seems genuine. His income and personal references check out. However when I ran his background check, he was successfully sued for rent just a year ago. I called the plaintiff and they told me the story of what happened, that I want nothing to do with him, and that he is potentially dangerous. He lied about some things on his application and I'm done with him.

My question is: Should give him a reason I rejected his application, or just simply cut off contact? I am concerned he could become vindictive.