The primary authority on this subject in California is Civil Code section 1710.2, which states that "no cause of action arises against an owner of real property or his or her agent, or any agent of a transferee of real property, for the failure to disclose to the transferee the occurrence of an occupant's death upon the real property, or the manner of death where the death has occurred more than three years prior to the date the transferee offers to purchase the real property . . . ." However, section (d) of the statute indicates that "notwithstanding subdivision (a), an owner of real property or his or her agent has a duty to disclose the occurrence of an occupant's death upon the real property, or the manner of death of which they have knowledge, in any case where the transferee makes an inquiry concerning deaths related to the property."
So the general rule is that a death within three years of the offer should be disclosed, and that any known death should be disclosed upon specific inquiry by the buyer.
There are a few clarifications that may apply: (a) A "notorious" death such as a murder, or infamous murder, may be an exception. For instance, a buyer's attorney might argue that the notoriety and its effect on the property create separate issues from the death itself; (b) Some cultures often are concerned with death on a property, particularly depending on the age of the decedent and circumstances. In these circumstances, the issue is likely to arise at some stage and disclosure may prevent a late cancellation or other problems; and (c) Many brokers and agents may feel that a death should be disclosed regardless of time or circumstances. If a death has occurred, the issue can be discussed with your agent as to what course seems appropriate.