There is no federal law requiring this, so it comes down to individual states. You can get a good feel for the issue here:
http://www.nolo.com/legal-encycloped...eath-here.html
For MS: Not required unless it affects the material value of the house. Example would be a meth lab fire that killed someone, but mostly due to the hazardous chemicals from the meth lab and not the killing.
§ 89-1-527. Failure to disclose nonmaterial fact regarding property as site of death or felony crime, as site of act or occurrence having no effect on physical condition of property, or as being owned or occupied by persons affected or exposed to certain diseases; failure to disclose information provided or maintained on registration of sex offenders (1) The fact or suspicion that real property is or was
a) The site of a natural death, suicide, homicide or felony crime (except for illegal drug activity that affects the physical condition of the property, its physical environment or the improvements located thereon);(b) The site of an act or occurrence that had no effect on the physical condition of the property, its physical environment or the improvements located thereon;(c) Owned or occupied by a person affected or exposed to any disease not known to be transmitted through common occupancy of real estate including, but not limited to, the human immunodeficiency virus (HIV) and the acquired immune deficiency syndrome (AIDS);does not constitute a material fact that must be disclosed in a real estate transaction. A failure to disclose such nonmaterial facts or suspicions shall not give rise to a criminal, civil or administrative action against the owner of such real property, a licensed real estate broker or any affiliated licensee of the broker.