Direct from the California Department of Real Estate:
"No cause of action arises against an owner or the ownerâ€™s broker/agent (or any cooperating broker/agent) when selling, leasing, or renting real property for failing to disclose to the buyer, lessee, or renter the following:
â€¢ the manner or occurrence of an occupantâ€™s death upon the real property if the death occurred more than 3 years prior to the transfereeâ€™s offer to purchase, lease, or rent the property; or
â€¢ that an occupant of the property was afflicted with, or died from, Acquired Immune Deficiency Syndrome (AIDS).
This controlling statute does not change the law relating to disclosure of any other physical or mental condition or disease of an occupant or the physical condition of the property. If the buyer asks a direct question concerning deaths occurring on the real property, this statute will not protect the owner or broker(s)/agent(s) from misrepresentations.
(CAL. CIV. Â§ 1710.2)"
So the statute says you must disclose if it has occurred within the past 3 years.
Solant Real Estate Advisors