Unacceptable Tenant Behaviors

[Brian Kennedy]

I received a complaint from a neighbor that my tenant's son was climbing on the room of my single family rental (Section 8 in NJ).   I didn't see it happen and at the time had reason to question whether the accusation was true.    I confronted my tenant as a conserned parent and explained that I first and foremost didn't want anyone getting hurt.   I then explained that if true, the behavior was unacceptable.  She spoke to her son and he swore that he wasnt on the roof. Fast forward to this week. I received a complaint from 100% reliable source that the tenant's kid was not only on the roof, but jumping from the roof to a trampline.   I don't want to necessarily evict this tenant, if thats even possible, but I need this behavior to stop. What are my legal rights and have any of you experienced this before?   I cant find anything any law that directly addresses this type of behavior.   

Thanks, 
Brian