I'm no attorney, but a quick google search brought me to this site. 

We renovated 2 of the units including bathroom remodels, and brought them up to a “classic plus” finish - the rents and market wouldn’t support high end finishes like new appliances and granite countertops.

My real estate agent brought this off market deal to me from a local wholesaler.

At some point after that, the other unit(s) were brought on-line again without the benefit of a building permit.If it's really important to you and it sounds like it is, I would suggest starting with a knowledgeable attorney so that you don't tip your hand in the wrong direction with the City.  

So we fired him after we saw all that terrible work and then ordered an inspection report to see what was left to fix. turns out 80% of the work was not up to code and the house was dangerous unless we brought in guys who where specialist and did things up to code.

I would 100% absolutely NOT rent to these people, unless they can prove that the charges were falsely brought about (i.e. true slander).The fact that the crimes relate to aggressive and violent behavior is what's most concerning.

When this deal was brought to me, I ran the numbers and it looked good.

As your investing progresses you’ll realize the needs for additional LLCs or those needs will be brought up by your attorney or accountant.  

(oddly though they hadn't been monitoring value over the past 3 years and recommending raising rent gradually until I brought it up)  Anyway, they confronted the tenant when they paid their rent and told them that rent was being increased by $150 and if they didn't want to pay the new amount, they could vacate by the end of the month. 

The same wholesaler brought me another similar deal two weeks later.