UDs (Unlawful Detainer) do show up in public records. By stating that they are being difficult and that there have been hearings, etc...I am guessing that they are in this process.
If you have, or know someone who has access to Westlaw (usually an attorney has this) you should be able to find it there and see exactly where they are in the process. Generally, court records are public records...but there is always the possibility that something has happened in the case that would restrict it from public view. No way to say for sure without knowing what has happened in the case. A charming catch-22 I am aware.
I read this, but not closely:
New Jersey Forcible Entry and Unlawful Detainer Act
and it does not appear to state that UDs are sealed in anyway.
So, maybe read this closely, decide where you think they are in the process and go from there?
Or, as dealing with the courts can be less than enjoyable if you are not familiar with the system, it may be a good idea to pay an attorney for a couple hours of his time to find the information for you.