Legal Question in Landlord & Tenant Law in New Jersey

Re: secretly recording someone

It depends. The States differ and it everywhere depends on the circumstances. In NJ, a safe rule of thumb is if you can hear it yourself, you can record it. So, bringing a recorder with you is okay. Leaving a recorder running while you leave the room is not okay unless the people in the room know about it. Using an amplifying mike to listen to your neighbors is invasion of privacy. Telephone conversations can be taped in NJ with ther permission of one of the parties to the conversation.

See also: http://info.corbettlaw.net/lawguru.htm