As professional on public forum i hate hear about a tenant getting sick or dying cause a Landlord flipping a mold infested property or renting out didnt want hire professional in this case it can be someone health immune system or life that gets damaged. 

But these incredible neighborhoods have fallen into such disrepair, crime-ridden, drug-infested.  

I was the mortgage broker for a buy and hold investor that ventured into a drug-infested neighborhood and purchased two homes for $145,000 each, the pig's wearing lipstick.

Here in California it is the landlords responsibility to remediate any infestation issues (mice, roaches, bedbugs etc.) however you can bill the resident because you would not of brought this into their unit.

I had a detached 2 car garage that the home inspection found lots of sill plate and stud termite damage from an old infestation.

Long Beach has some good areas, midline areas, and some gang infested areas, right?

To ensure warranty of Habitability, I arranged payment in full to ensure the infestation didn't spread and that it would be completed as quickly as possible.  

As a buyer, it would be a bag of worms.For instance, say a tenant advised the seller a while back of mold problems and infestation problems, you sold the equity, no estoppels, the buyer would have no idea of this.

Year 3 and 4, roaches.Well, year 1 and 2 the house was pet free, then they got a cat and a dog on year 3.Each time they had noticed an infestation, it was after they took a vacation.A vacation where they left the cat in the house, and had a friend come by every two days and opened a few new cans of cat food and spread them on a plate. 

We dealt with an infestation of bigger than mice creatures in a 15 unit building and were surprised at the extent of the protocol involved.