My question involves defamation in the state of: Oregon

At my former apartment, and here at my new home there is/was a registered sex offender.. a pedifile. No one knew except his girlfriend at least that is one tale I have been told.
I cancled letting her move in with us.. well she did when I told her he was not welcome on the property. I have all the court documents you can get, the rest are sealed because the victim was a minor, and suspect a mentall deficient minor at that.
I have informed both property managers of this.. hence he has lost any chance of living there.. not that he was ever on the lease at the apartment. Thehouse mamangers insist the minute he shows up.
So.... is that defmation?