In every real estate transaction where the seller has recently occupied the property, you are obligated to fill out and give the buyer a copy of the seller's property disclosures. In Oregon, these disclosures are four pages of literally hundreds of questions about the property. It's a means for the buyer to gain as much knowledge about the property from the seller as possible. Currently, my favorite seller's property disclosure question is "has the property ever been used as an illegal drug manufacturing or distribution site?" I can honestly say I've never been involved in a transaction where a seller answered "yes". There are many other "defects" that are addressed in the property disclosures, and several that are not. Yet.
In California, the seller is obligated to disclose if a murder has taken place in a property in the last three years. In Oregon, we are not. The evidence is there; properties that were the scene of violent crimes, especially grisly, well publicized crimes, significantly reduce the value of a property. Let's take, for instance, 924 N 25th St apt #213, Milwaukee, WI. Can you guess whose apartment this was? Jeffrey Dahmer. The entire building was razed shortly after Dahmer was arrested.
In every case, the property is cleaned and remodeled, with some owners going so far as having the address changed. Would you buy a murder house?