On the morning of December 30, 1982, 28-year-old Gail Mark was found stabbed and strangled in the bedroom of her duplex in Manhattan’s Murray Hill. Her three-year-old daughter was discovered locked in a bathroom, physically unharmed but traumatized; the child identified the attacker as E.T., a reference to the movie character whose mask the killer had worn. A pillow had been placed over Gail’s face.

From the start investigators focused on Gail’s husband, Franklin Mark. The couple had a tumultuous marriage; Gail had once begun divorce proceedings and had told others she feared Franklin might physically harm her, even mentioning a fear of being stabbed. Friends and family described ongoing strife. Despite those suspicions, police did not have enough evidence to charge Franklin, and he has denied involvement.

The case was reopened in 2015 after Franklin’s sister filed a sworn affidavit saying it was common knowledge in the family that Franklin was responsible and may have hired a hitman. Much of the physical evidence, including the E.T. mask and a swatch of blood-stained carpet, had been lost or destroyed over the years, and no arrests have been announced. Does anyone have information about the household, neighbors, or the investigation around 1982 that could help fill gaps in this case?