Gene Hackman Died More Than A Week Before He Was Found, Sheriff Believes

The Santa Fe County Sheriff's Department held a news conference to give an update on the investigation into the deaths of legendary actor Gene Hackman and his wife, Betsy Arakawa, this afternoon -- and, it sounds like Gene was dead in the New Mexico home for a week and a half before he was found.

Sheriff Adan Mendoza led the news conference as deputies continue to look into the deaths they labeled "suspicious" in a department application for a search warrant this week.

During the press conference, Mendoza says Hackman's pacemaker shows its last event on February 17 -- indicating that's when it stopped and when he died. Mendoza said autopsies and toxicology reports were pending, but he said both individuals tested negative for carbon monoxide, according to the medical examiner.

Mendoza is laying out the timeline of events ... explaining how officers discovered Hackman, Arakawa and their dog deceased in the home. Animal control got involved to ensure the two living dogs -- who appeared healthy -- were kept safe.

Mendoza says there were no surveillance cameras inside or outside the residence that could aid officers' investigation. They're working to determined when Gene or Betsy last contacted anyone.

As you know ... Gene and his wife Betsy were found dead in their home Wednesday afternoon after a caretaker of their neighborhood dialed 911 to report seeing a body in the couple's house, and deputies responded to conduct a welfare check.

The caller was incredibly emotional ... and, when first responders arrived, they found Hackman, Arakawa and one of their dogs unresponsive. The three were pronounced dead at the scene.

Cops are looking into the deaths they've labeled as suspicious for a variety of reasons ... like numerous pills spilled out on a bathroom counter, an unlocked front door, and no obvious signs of a gas leak.

The sheriff and the Santa Fe fire chief spoke on "TODAY" Friday morning and admitted they weren't ruling out the carbon monoxide poisoning theory ... since the bodies weren't found for some time and gas could have dissipated. But the press conference dispelled that notion.

Hackman was 95 ... Arakawa was 65.