Authorities determined a cause of death for actor Gene Hackman and his wife Betsy Arakawa, New Mexico chief medical examiner Heather Jarrell announced Friday.

“I'd like to begin by stating that it is unprecedented for the office of the medical investigator to make public statements about death investigations,” Jarrell said at a news conference. “However, the circumstances surrounding these two deaths require accurate dissemination of important information.”

On Feb. 27, the day after the 95-year-old actor and his 64-year-old wife were found dead, the office performed autopsies.

Hackman’s cause of death was determined to be hypertensive and atherosclerotic cardiovascular disease. He was in an advanced state of Alzheimer’s disease, Jarrell said, explaining that he might have died without knowing about his wife’s condition. He did not show signs of dehydration.

Arakawa’s cause of death was determined to be hantavirus pulmonary syndrome.

Hantavirus is a rare disease that can be transmitted to people through rodent urine, droppings or saliva. According to the Centers for Disease Control and Prevention, it can cause respiratory failure, and symptoms include coughing and shortness of breath.

Dr. Erin Phipps, a state public health veterinarian with the New Mexico Department of Health, said there are between one to seven infections recorded in New Mexico each year, 42% of which are fatal.

There were no findings of trauma or other viruses. Carbon monoxide poisoning had previously been ruled out. Pills found at the scene were thyroid medication being used as prescribed.

There was no way to determine Arakawa’s time or date of death, but Santa Fe County Sheriff Adan Mendoza said the last time she sent electronic communication was Feb. 11.

The last day that cardiac activity was recorded on Hackman’s pacemaker was Feb. 18, which Jarrell said might have been the day he died.

A dog named Zinna was also found deceased, and authorities are still awaiting necropsy results to determine a cause of death. Arakawa picked Zinna up from the vet on Feb. 9, which may explain why the dog was in a crate.

Mendoza said they will consider this an open investigation until they receive the final requested cell phone information, but they’re “pretty close” to knowing the full timeline of events.