Gene Hackman death investigation timeline: Detectives working 'backwards' to determine how couple died

Detectives described their deaths as "suspicious enough in nature to require a thorough search and investigation," according to a search warrant affidavit obtained by Fox News Digital. 

"One of the things is, in an investigation, we try to piece the timeline together, usually before the event happens, and that gives us a lot of information," Mendoza said. "But in this case, it seems like we're doing a reverse timeline. 

He added, "We're doing a timeline from the time of death and the autopsy and the results. We're going to start working our way backwards. We're going to do both and then hopefully make a determination as to what may have happened to both of the individuals."

Sheriffs released a search warrant inventory list detailing items retrieved from the Santa Fe home. According to the documents obtained by Fox News Digital, investigators listed two cell phones, MyQuest records, a 2025 planner, thyroid medication, blood pressure medication and Tylenol.

An orange prescription bottle was found near Hackman's wife, according to the search warrant affidavit. It appeared to be open, with pills scattered on the countertop.

Arakawa was found lying on the floor in the bathroom of the couple's home near a space heater, showing "obvious signs of death," according to the search warrant affidavit. Hackman's body was discovered in the mudroom nearby. His cane and sunglasses were near his body.

Officials revealed that Arakawa's body had been found decomposed with bloating on her face and mummification in her hands and feet. Hackman was also found to have the same signs of decomposition as his wife. 

The Santa Fe County Sheriff's Department revealed that autopsies were completed, and no external trauma was seen on either the actor or the musician.

LISTEN: GENE HACKMAN 911 CALL

WATCH: SANTA FE COUNTY SHERIFF ADAN MENDOZA DISCUSSES THE INVESTIGATION INTO GENE HACKMAN's AND HIS WIFE'S DEATH

The New Mexico Gas Company confirmed on Tuesday "it conducted an extensive investigation for gas leaks and carbon monoxide" Feb. 26 and made "no significant findings" at the couple's secluded home, in a release obtained by Fox News Digital.

The gas company did note there was "a minuscule leak (0.33% gas in air - not a lethal amount) at one of the stove burners." Additionally, there were four "red tags" for code enforcement violations, involving "a water heater and gas log lighters installed in three fireplaces."

"According to the pathologist, I think that is a very good assumption that that was his last day of life," Mendoza said.