James Gill, Chief Medical Examiner, with the Connecticut Office of the Chief Medical Examiner, is not investigating Hackman's death in his professional capacity. But he offered insight into the tragedy to PEOPLE, theorizing that a “companion suicide” — where a couple dies by suicide together — is not likely.

New Mexico Gas Company "conducted an extensive investigation for gas leaks and carbon monoxide" at the property, the Santa Fe County Sheriff's Office said.

The two surviving dogs belonging to actor Gene Hackman and his wife Betsy Arakawa "are safe and adjusting" after the couple was mysteriously found dead.

Multiple accounts from family and those close to the late actor and his wife indicate the couple withdrew from everyone in their final days and weeks.

The deaths of Oscar-winning actor Gene Hackman and his wife Betsy Arakawa were not due to a gas leak, authorities in New Mexico said Tuesday.

Hackman and his wife, Betsy Arakawa, were described as private but neighborly by those who got to know them over many years.

It was revealed that authorities had initially misidentified the diseased dog that was found dead in Hackman’s home.