Autopsies revealed that Hackman and Arakawa both died of natural causes, though their deaths are attributed to different causes and could have happened several days apart, Jarrell said.

Hackman probably died on February 18, when his pacemaker last recorded his heartbeat. The device recorded that the actor was experiencing atrial fibrillation, an irregular heart rhythm.

Hackman was hypertensive and died of atherosclerotic cardiovascular disease, Jarrell said. He also had advanced Alzheimer’s disease, which the medical investigator said was “a significant contributory factor.” A postmortem CT scan showed that the 95-year-old had severe heart disease and chronic high blood pressure.

Arakawa, who was last seen in public about a week before her husband’s likely time of death, died first from hantavirus pulmonary syndrome. The syndrome is the result of hantavirus, a rare disease that can infect humans through contact with infected rodents, Jarrell said.

It appears likely that Betsy died in the home before her husband, investigators said, and it is possible Hackman was in the home with his wife’s body for several days before he died.

“It’s quite possible that he was not aware that she was deceased” due to his advanced Alzheimer’s, Jarrell said when asked whether Hackman was aware his wife had died. She noted he was in a “very poor state of health.”

Arakawa was last seen alive or heard from February 11, when she had a short email conversation in the morning with her massage therapist before driving into Santa Fe to run errands, according to Santa Fe County Sheriff Adan Mendoza.