In California, you are expected to disclose the death of a resident that happened in your home or apartment before you can sell or lease it.
This requirement is for the past 3 years before the sale or lease. If the death occurred more than 3 years ago, then no disclosure is required.
The manner of death is expected to be disclosed, unless the deceased died from AIDS.
(Ref. CAL. CIV. § 1710.2)