Nightmare tenant - how to remedy?

[Ian Loonce]

I have a duplex near a university.  It's close to the university but also close to the bad part of town.  It can be hard to find good tenants, sometimes we get lucky.

I was living upstairs in the duplex and the management company just put in some new tenants.

They have been a nightmare.  The girls boyfriend is living there illegally not on the lease.  They have been possibly distributing drugs.  They smoke marijuana daily on the property.  They complain non stop.  They recently found out somehow that I am one of the owners of the property.  They started harassing me to give the other owners number because they were upset that it wasn't clean enough when they moved in a month ago.  We gave them 25$ off rent and it's only 550 a month.  It had been cleaned multiple times but the fridge and stove were a little dirty.  So I gave them that.  The guy raised his voice at me and said "you're about to make me mad!" when I wouldn't give my partners contact info or give them more money off rent.

I didn't feel safe to I moved to another unit of mine.  I brought a police officer to monitor the move.  They were still harrassing me in front of the police officer to give them my partners contact info so they could try to get more off rent. 

The company suggested a 10 day notice for them to remedy him living there illegally.  Is there anything else I can/should do?