All the utilities are off, but on further investigation one of the units is occupied by a squatter, living there for who know how long without utilities. 

We got enough evidence for that.Now she took a property manager exam and said she will be meeting with Commission to complaint against our property management practices to start investigation.  

Why landlords waste time trying to investigate a applicant that clearly should not pass screening on the surface information collect is beyond understanding.

I was just curious how your overall experience was with investigating the flipping market here @Tim Kunz and any tips you might have for someone who is new to the area.  

There could be some cross paths worth investigation especially for the more insightful longterm investors.

Check out this news story. http://www.wearegreenbay.com/news/local-news/local-5-investigates-rent-to-own

I have thought about getting someone to stop by for things that need further investigation but wouldn't have to pay 10-12% of gross annual rents to.

I think you should report that agent to the realtor's governing body and have that investigated...I'd guess the realtor could lose their license if there is a way to prove what they have been doing.

I checked out flipping, getting my RE license, buying low-cost homes in rural parts of the country, investigating mobile home parks, etc.  

But does it hurt to investigate?