It was in a historic neighborhood but the house was funky and had foundational issues, mold and obviously a roach infestation.

I'm assuming he didn't have any issues with the place - the only way I could see him winning is if there was a health issue that wasn't addressed (broken water heater, bug infestation, etc.). 

Look for insect infestations, signs of previously backed up plumbing, leaks, broken windows, condition of the furnace... you can get a good feel for how a place was cared for.

It's typical to find a beautiful quiet neighborhood, and a couple of blocks down run into a crime infested patch.

The Tenant acknowledges that the Landlord has inspected the Premises and is aware of no rodents, bedbugs, or other infestations.

This propriety has a good bit of water damage, a bad roach infestation, disgusting smells, replaced roof, etc.

Did some reading here and saw some great ideas like letting them know if the infestation returns its at their expense, but with it being a 4 plex I don't want them to let it go untreated and cause issues for other tenants as well.

HOME PARTNERS OF AMERICA WILLINGLY PUT US IN A BLACK MOLD INFESTED HOMEThey refuse to give us inspection report that we were told was done and passed.

By the time the Exec. got the property back from the state it was $40k behind in back taxes, rat infested and TOTALLY trashed.

Today was the termite inspection and both houses have some infestation - one has evidence of old and one has evidence of active.