Gene Hackman and his wife, Betsy Arakawa, tested negative for carbon monoxide poisoning officials said Friday as they continue to investigate what caused the couple's deaths. The pair were found dead at their Santa Fe,

Santa Fe County Sheriff Adan Mendoza told NBC's “Today” show that investigators were trying to sort out conflicting stories about the doors. He said several doors were unlocked and a rear door was open, which allowed two dogs that survived to go in and out. He also said he thinks the front door was closed but unlocked.

Arakawa “hadn’t called” her 91-year-old mother, Yoshie Feaster, who suffers from dementia, since October, according to the elder’s housekeeper, Keiko. Keiko spoke to Daily Mail on Friday, just two days after Hackman, 95, and Arakawa, 65, were found dead in their Santa Fe, New Mexico, home, along with a deceased dog.