HOW DO YOU DEAL WITH HORRIBLE NEIGHORS???

[Melissa Harris]

I own a townhome, that has an attached wall with another townhome. This townhome was built in 1971, so the wall between the units are not insulated very well. The tenants that live in the unit next to mine, are landlords worse night mare! They are very dirty, drug addicts and they cause fights within the community all the time! My tenants have complained a few times about how they have tried to start fights with them and on top of this, the neighbors smoke cigarettes/weed in their unit, which is causing the smoke smell to come through the walls into MY unit. They say somedays it is extremely strong, I have witnessed the smell when I came into the townhome.(this was an issues as well when I was occupying the unit) My tenants don't want to cause any more issues with the neighbor because they are just 3 months into their 1 year lease. But they would like to come up with a solution in order for them to feel safe and not have their unit smell like smoke. 

My question is: What have you all done with bad neighbors? The rental is in Colorado, so I am wondering if their are any legal aspects when it comes to dealing with neighbors that could cause my tenants to vacate and not live their anymore? Would the HOA be able to have the owner evict the bad neighbor? FYI, the bad neighbor rents from their aunt and uncle.

Any suggestions would be truly appreciated! Thank you.