If something seems too good to be true, it either is or needs more investigating. 

You need to call a local real estate attorney to where the property is located and tell them to deal with this mess immediately.Depending on the state where the property resides,the buyers agent should be responsible to have to perform a final walk through inspection and agree in writing that the property is ready for acceptance.Demand to see the paperwork again and talk to The the agents broker of record to investigate whether or not their agent performed their duties.

On one memorable occasion I was investigating a 30+ unit commercial property.

However, upon further investigation, buildings are *really* expensive.

It's not what it seems.Have fun researching and investigating!

I looked at a home to buy and hold and found a small puddle of water by the back wall of the basement. there was staining about 2" up from the floor that indicated it is a known issue. so I investigated outside and found the gutter overflowing at the exact time location outside. and the clogged downspout coming off the gutter in the middle of the house and not on an end. should I be overly concerned or would a proper gutter and drylock in the basement solve this issue. other then this the house would cash flow well with some updating. by the way this would be my first investment property.

When researching markets, I do not take the housing itself into consideration before moving forward and investigating a market.  

I'll have to investigate that as well.

The police are still investigating, but it sounds like the tenant's daughter's friend's boyfriend (I know that was complicated) is the culprit.

I follow strict models with the 1% rule or better in my investing and I'll be doing a great deal of investigation into my future partner(s) and markets.