In the state of Texas, the only time it is required to disclose if there was a death in a property is if the death was due to unnatural causes or something caused because of the property itself. If someone died of a heart attack in their sleep, then legally it would not have to be disclosed.
Often if you have a target address, you can go to the local police department and ask for a list of any calls to that address by police, fire, or EMS. That information is public record. That may help you in your search.