Authorities are searching for answers into the death of actor Gene Hackman, 95, who along with his wife, Betsy Arakawa, 65, were mysteriously found dead in Santa Fe.

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.

The investigation into the mysterious deaths of actor Gene Hackman and his wife, Betsy Arakawa, at their home in Santa Fe, New Mexico, entered its third day Friday with more looming questions than answers.