Frederick Hengl, 69, was being treated for prostate cancer. The San Diego County district attorney said he died in the jail infirmary Sept. 27, U-T San Diego reported.
Police who went to Hengl's home in Oceanside last November because of complaints of a foul odor found the remains of Anna Faris. The head was in the refrigerator and other body parts were on the stove.
Court proceedings had been postponed because of Hengl's illness. A hearing had been scheduled for Nov. 18.
Faris reportedly suffered from Alzheimer's disease.