Try your local Sheriff's office to research if this is important to your buying decision.
If a buyer is worried about events that have occured with previous owners then they probably should never buy any home and live in a van down by the river.
Even when building from the ground up, it's not possible to determine if someone may have taken their own life (at any time previously, ie. back to the 1800s) on that plot of land.
All the best,