The relationship between a property's violent history and its market value is way more complex than just a blanket 'it drops.' I used to work adjacent to real estate data, and the initial impact is almost always negative – you get the immediate stigma, media circus, and a severely limited buyer pool. But that's just the first chapter.
Long-term, it depends heavily on cultural memory and repurposing. Places like the Amityville house have their notoriety baked into the price now; they're dark tourism landmarks. Others, if enough time passes or the story is localized/forgotten, can rebound, especially if the architecture or location is desirable. Renovation and a new name often help, but disclosure laws vary, which adds another layer.
Personally, I find the psychological pricing fascinating. Some buyers see a discount as a fair trade for the 'baggage,' while others perceive an irredeemable taint that no money could offset. The final sale price ends up being a direct reflection of how many people in that specific market fall into the latter category.