Arakawa was reported to have died from hantavirus pulmonary syndrome, caused by hantavirus, which spreads through rat and mouse urine and droppings commonly picked up when a person cleans attics or basements. Rodent feces was reported to be found in three garages, two casitas and three sheds on the property, while a live rodent, a dead rodent and a rodent nest were all located in the three detached garages.

Two vehicles on the property were also reported to have signs of rodents during the investigation. Live traps were also reportedly set up in the outbuildings, which suggests that the couple had been dealing with an ongoing infestation.

Santa Fe Sheriff Adan Mendoza updated the projected date of Arakawa's death after reviewing a doctor's claim that he received a call from her on February 12, one day after the medical examiner's originally concluded date of her death on February 11.

“That would indicate to me that she was seeking medical advice or medical help and may have not been feeling well,” Mendoza said on Good Morning America on March 18.

On March 17, Dr. Josiah Child, who leads Cloudberry Health in New Mexico, told the Daily Mail that he received a call from Arakawa, 65, on February 12.

“Mrs Hackman didn’t die on February 11 because she called my clinic on February 12,” Child told the Daily Mail. “She’d called me a couple of weeks before her death to ask about getting an echocardiogram [heart scan] for her husband.”

The doctor also claimed that Arakawa had called to schedule an appointment for her own unrelated respiratory problems.

“She was not a patient of mine, but one of my patients recommended Cloudberry to her,” he said before claiming Arakawa canceled her appointment due to Hackman, 95, feeling ill.

“She called back on the morning of February 12 and spoke to one of our doctors who told her to come in that afternoon,” Child added. “We made her an appointment but she never showed up. She did not show any symptoms of respiratory distress. The appointment wasn’t for anything related to hantavirus. We tried calling her a couple of times with no reply.”

Hackman was reported to have died of hypertensive cardiovascular disease with Alzheimer's as a factor, while Arakawa was reported to have died from hantavirus pulmonary syndrome, New Mexico State Chief Medical Examiner Dr. Heather Jarrell confirmed. Arakawa is suspected to have died first as all outgoing communication from her cellphone and email ceased on February 11, the last day she was spotted publicly, while Hackman is suspected to have died on February 18, as it was the last day his pacemaker registered data, though

Dr. Jarrell specified that there was no reliable scientific method to determine an exact time for either death. Officials reiterated that foul play was not suspected in Hackman and Arakawa's deaths and the scene was tested for carbon monoxide, with only a minute leak found that was deemed to be insignificant.

Hackman, a two-time Academy Award winner, and his wife were married for 34 years. Police reportedly found the couple at around 1:45 p.m. local time on February 26. Hackman's legendary acting career spanned more than 60 years, providing an everyman believability to numerous iconic roles, including playing Jimmy Doyle in The French Connection (1971) and Little Bill Daggett in Unforgiven (1992), which won him the Academy Awards for Best Actor and Best Supporting Actor, respectively.

The California native was also nominated for Best Supporting Actor for roles in Bonnie & Clyde (1968) and I Never Sang for My Father (1971), as well as Best Actor for Mississippi Burning (1989). Hackman is also remembered for playing arch villain Lex Luthor in Superman (1978) and Superman II (1980), as well as Coach Norman Dale in Hoosiers (1986) and Royal Tenenbaum in The Royal Tenenbaums (2001) among numerous other iconic roles.