dope in the garden state

[Lloyd Spencer]

tenant 2 complained that tenant 1 was smoking so much dope that her kids are getting high in the upstairs unit. smoking and illegal activities are lease violations so i sent a notice to cease on Sept 1 via certified mail and tenant 1 contacted me about it at the time. fast forward to today, another complaint from upstairs. they say they are considering calling the police, I say go ahead. preliminary conversations with attorneys indicate that eviction for things other than non payment are expensive/difficult in NJ. approx 9 months to go on both leases. what are my responsibilities in this scenario? I can't easily get evidence of the activity. should I just wait it out? so far both pay on time.