SANTA FE, N.M. — Preliminary autopsy results didn’t determine how Oscar-winner Gene Hackman and his wife died at their home in Santa Fe, New Mexico, but did rule out that they were killed by carbon monoxide poisoning, the sheriff leading the investigation said Friday.

The condition of the bodies found Wednesday indicated the deaths occurred at least several days earlier and there was no sign of foul play.

At a news conference, Santa Fe County Sheriff Adan Mendoza said the initial examination by the medical examiner showed no sign of carbon monoxide, a colorless and odorless gas produced from kitchen appliances and other fuel-burning items. When it collects in poorly ventilated homes, it can be fatal.

Mendoza also said an examination of the 95-year-old Hackman’s pacemaker showed it stopped working on Feb. 17, which means he may have died nine days earlier.

Hackman’s body was found in an entryway. The body of his wife, Betsy Arakawa, 65, was in a bathroom. She was on her side and a space heater was near her head. Investigators said the heater likely was pulled down when she fell. There also was an open prescription bottle and pills scattered on a countertop.

Whether the pills or other drugs were a factor won’t be known until toxicology tests are completed in the coming weeks.

Dr. Philip Keen, the retired chief medical examiner in Maricopa County, Arizona, said it would be unlikely for a person who tests negative for carbon monoxide initially to later be found to have been poisoned by it.

He also said the moment when a pacemaker stops working could mark the point when a person dies, but not always.

“If your heart required a pacemaker, there would certainly be an interruption at that point — and it might be the hallmark of when the death occurred,” Keen said. “But it’s not necessarily because some people get a pacemaker to augment things, not necessarily replace things.”

Investigators planned to comb through the couple’s phones and monthly planners and reach out to family members, neighbors and workers from the gated community to figure out the last time anyone saw or spoke to Hackman or Arakawa.

The couple was a “very private family,” Mendoza said, making it challenging to piece together a timeline.

Authorities do not believe the home had any surveillance cameras, he said.

Authorities who later searched the home retrieved medication that treats high blood pressure and chest pain, thyroid medication, Tylenol, and records from medical diagnostics testing, court records filed Friday showed.

Detectives wrote in a search warrant affidavit that investigators thought the deaths were “suspicious enough in nature to require a thorough search and investigation.”

No gas leaks were discovered in or around the home.

A maintenance worker who showed up to do routine work at the house could not get inside and called a security worker who spotted two people on the ground, Mendoza said.

The worker called 911 and told an operator he did not know if they were breathing.