I bet if it had been a hidden cache of drugs, the homeowner would have been hit with all sorts of drug charges and have the home confiscated via civil asset forfeiture.
Because that's how they roll here in PA.
I have a relative that had something like that happen to them.. Bought a house at a Sheriff / Tax sale, which is basically buying sight-unseen. Hired a contractor to clean out and remodel the place. Workers found signs of drug activity.. scales, packaging material, a couple of rusted out guns along with a small amount of weed - called the police, police arrived with a warrant and despite clear evidence the drug activity took place some time ago (the house was abandoned nearly a year), ended up arresting the homeowner and charged them with the manufacture and distribution of drugs. The D.A. also started proceedings to confiscate the house as well. Took nearly two years and all but bankrupted them to get cleared of all charges and get to keep the house.