If you are willing to evict for this type of lease violation (smoking in the apartment), what evidence of smoking can you take to court?

Have your father in law go in with proper notice to check the furnace filter or smoke detectors and take a look at the interior, hope he has keys.. have him take photos of inside and out. 

But honestly, besides the occasional light bulb replacment, smoke detector battery replacement, HVAC filter replacement, your monthly repairs isn't all that much. 

My GC just notified me that the Baltimore City electrical inspector wants him to install (a) hard wire smoke detectors, (b) GFIs, and (c) replace electrical wiring in the entire two-unit building.

That alone means anyone can set-up a class and get a book deal just alot of smoke and mirrors.   

We schedule quarterly inspections to check the fire extinguishers, smoke alarms, air filters, and leaks under the sinks, which helps mitigate problems that would affect the health and safety of the tenant and costly repairs for the owner.  

A person walking their dog at that hour called 911 to report smoke billowing out from the roof. 

I lived in WA for nearly 20 years, from the White Salmon area to Seattle, Bellingham - I owned a house in Sumas on the Canadian border, too.You know what might work for Chelan for the workers who need to live there year round, is to find a LIHTC (low income housing tax credit) investor group to build an apartment complex or two in town. 

Pre-screen with lots of questions about how much they smoke, how many animals, etc.   

I owned property between White Salmon, WA and Trout Lake, WA, so I'm familiar with the area and the weather - though, not your specific city/county requirements.