Legendary actor Gene Hackman and his wife, Betsy Arakawa, reportedly stopped receiving guests and became more "insular" during the final years leading up to their mysterious deaths last week, longtime close friends, Daniel and Barbara Lenihan told the New York Post.

Daniel, 79, an author, said it had been "years" since he last saw Hackman, 95, his friend of more than 30 years, in person, while Barbara, 75, who owned a home decor store with Arakawa, 65, said she last saw the actor about a year ago. Barbara said she and Arakawa spent some time together earlier this year and had exchanged emails in the weeks leading up to their deaths, but claimed the couple had "become insular" in recent years.

“People loved to be around them,” she said via the New York Post. “We used to spend a lot of time at their house but it’d been a while since they were comfortable having others over. They were a little insular and that was fine, it just got tougher for them to have people over.

“We’re all deeply saddened. We’re all just in shock and can’t believe [that they are dead],” she added.

The Lenihans, along with their son Aaron, previously told PEOPLE that Hackman was "essentially kind of homebound" recently. Barbara acknowledged that the actor "quit riding his bike through the neighborhood" about a year ago as his health was "really slipping" in the "last couple of months," disputing a claim by Hackman's daughter, Leslie Anne, that her father was "in very good physical condition" in the lead-up to his death.

The couple did, however, acknowledge that Arakawa appeared to be in good health as Barbara described her as being "so fit" prior to her death.

“Betsy tried to keep him kind of active and engaged,” Aaron said via PEOPLE. “She was still trying to keep him as active and engaged and healthy as possible.”

Police are considering the deaths of Hackman and Awakawa to be "suspicious enough in nature to require a thorough search and investigation," according to a police affidavit obtained by TMZ last Thursday (February 27). A Santa Fe detective wrote that the "reporting party found the front door of the residence unsecured and opened," as well as "a healthy dog running loose on the property, another healthy dog near the deceased female, a deceased dog laying 10-15 feet from the deceased female in a closet of the bathroom, the heater being moved, the pill bottle being opened and pills scattered next to the female, the male decedent being located in a separate room of the residence, and no obvious signs of a gas leak."

The deputy reported that Arakawa was found lying on the ground in the bathroom with a black space heater near her head, believing the heater could have fallen after Arakawa abruptly fell on the ground. An orange prescription bottle was open with pills scattered on the countertop.

Arakawa appeared to be dead for some time prior to being found as her body was in a state of decomposition with bloating in her face and mummification in her hands and feet. Hackman was reportedly found in a separate room near the kitchen fully clothed and suspected to have possibly fallen as his sunglasses were next to his body.

The local fire department said there were no signs of carbon monoxide leak or poisoning, which was initially suspected to be a potential cause of death by Hackman's family.

"As of now, there are no signs or evidence indicating there were any problems associated to the pipes in and around the residence," the affidavit stated, according to TMZ.

Hackman, a two-time Academy Award winner, and Arakawa, were married for 34 years. Police reportedly found the couple at around 1:45 p.m. local time on Wednesday (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.