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.

Authorities have not ruled out that Gene Hackman, his wife, and a family dog were fatally poisoned by carbon monoxide or gas leak in their New Mexico mansion. Santa Fe’s fire chief told Today on Friday there were no signs of toxic gas when first responders arrived at the actor’s estate on Wednesday,

Gene Hackman's daughter, and some internet sleuths, speculate that the Hollywood legend and his wife died by carbon monoxide poisoning.