SANTA FE, N.M. (AP) — Oscar-winner Gene Hackman, his wife and one of their dogs were apparently dead for some time before a maintenance worker discovered their bodies at the couple’s home in Santa Fe, New Mexico, investigators said.

The bodies were found Wednesday. Denise Avila, a sheriff’s office spokesperson, said there was no indication they had been shot or had any wounds that would indicate foul play. But Santa Fe County Sheriff’s Office detectives wrote in a search warrant affidavit investigators thought the deaths were “suspicious enough in nature to require a thorough search and investigation.”

Hackman, 95, was in an entryway, and his 65-year-old wife, Betsy Arakawa, was lying on her right side in the bathroom. A space heater was next to her head and may have fallen when she abruptly dropped to the floor, according to the affidavit.

The New Mexico Gas Co. tested the gas lines in and around the home after the bodies were discovered. At the time, it didn’t find any signs of problems and the Fire Department found no signs of a carbon monoxide leak or poisoning.

A detective wrote that there were no obvious signs of a gas leak, but he noted that people exposed to gas leaks or carbon monoxide might not show signs of poisoning.

Results of autopsies conducted on both bodies are not available yet, sheriff’s officials said, noting that carbon monoxide and toxicology test results are pending.

The search warrant affidavit suggests that police appear to have a working theory that “some kind of gas poisoning” happened, but that they don’t know yet and aren’t ruling anything out, Loyola Marymount University law professor Laurie Levenson said.