This in common with people who smoke cigarettes.

Also if they are small burn marks it could have been cigarette burns.

No, normally it would be cigarettes.

There are very few exceptions such as for products that are harmful to children (cigarettes, alcohol etc.).

I also provided to him credible websites that explained how difficult it is to get rid of smoke, regardless of the cause (ie cigarette, fire, etc).  

@Nate Baumann let me start by saying I vape myself - I quit smoking and switched to vapor over a year ago without one cigarette since!

The tenants had extra people sleeping on every spare surface, hypodermic needles embedded in the carpets, used diapers thrown in a corner, holes in all the walls, cabinets torn down, cigarettes put out on every surface. 

Let's say an obvious junkie applies for your $600 apartment and he has no job, no Landlord reference, a 486 credit score, six kids from five different women and two of those women are currently sitting in his 1984 Oldsmobile smoking hand-rolled cigarettes and offering services to any man that walks by.

Greetings,I am currently house hacking in CT and I have a question about how to navigate a situation The situation is: I am in the eviction process (lapse of time) for my tenant neighbor, and there are some serious te...

Lately, there have been other issues, such as smoking cigarettes in his unit and playing loud music late at night as well.