I called the police, an offer came out to the property, and told me to start a criminal trespassing case against him because they can't do anything about it until it's officially a criminal offense. 

I just want to clarify that i would not get confrontational with these people as i have learned how to interact with authority through out my life. police and i for example get along great.

If you are within the city limits you get all the city service, water, fire, police, garbage, and so on.

He stresses that while septics are built to be approved for a certain number of bedrooms, let’s say 3, generally there is no septic police to monitor that once you’ve got the original permits and the original property is built.

I'm 22 years old working in the Air Force Reserves (Hoping to get a civilian job soon with the police department).

You would then become a 'person of interest' as to the police investigator.

I don't believe there are any fannie mae 'POLICE" that check the property after closing.

(as the renter may be under duress to allow it, afraid of the peddlers, and will not want the police involved due to retribution).Do you just fail to notice this and collect the rent; or try to counsel them or (???) 

And the police would only go in there if they were called in for an emergency.  

I called the police right away.