I know the landlord has previously told the problem tenants what has been alleged by other residents and that it must stop. It's beyond warnings now. They have involved the police and my guess is that they will soon have information and proof needed to go foreword with a successful civil legal process. Like you said it's a process but in my case the landlord has told me it will definitely end sooner than later. No question about that.

As soon as they are gone my anxiety and depression will be totally gone as well. I have learned through this situation beyond a doubt that environment is so critical to mental and physical health.