Harriet A. Isaac, 64, a woman, was found dead on October 24, 1986, inside her condominium at 4999 Kahala Avenue in Honolulu, in the Kahala Beach area. She lived alone in a second-floor residence, and the quiet routine of the building was what first signaled that something was wrong: neighbors noticed her morning newspaper still sitting at her door around midday, unusual enough that they alerted building staff and security.
When repeated knocking brought no answer, security contacted police, and the door was opened to a scene that turned the calm of the beachfront complex into a closed-off crime scene. 
Inside, she was discovered in the hallway, and police described a violent attack—multiple stab wounds inflicted with a knife—followed by an eerie attempt to cover what had been done, with her body left beneath a blanket. Investigators and medical personnel moved through the apartment and began a careful search for evidence, while the body was transported to the medical examiner's facility later that day. 
What made the case even more unsettling was what detectives said they did not find. There was reportedly no clear evidence of a break-in and no obvious signs that the apartment had been ransacked or disturbed as if someone had been hunting for valuables. Even so, detectives stated they believed foul play was involved and treated the death as a homicide, pressing forward in a building where residents were shaken by the violence and the sense that it had happened behind what many considered secure doors. 
As investigators worked, they notified her daughter, who was in Hawaiʻi at the time. Reporting around the case also noted that Isaac had been estranged from her husband in recent years and that he no longer lived in Hawaiʻi, while describing the couple's move to Honolulu from California in the early 1970s. The same reporting pointed to earlier crime in the area—an incident years prior in which another resident in the complex was assaulted during a robbery—an unsettling reminder that even a well-kept property could attract danger. 
Publicly available police information continues to list Isaac's killing among Honolulu's cold cases, and the materials released by the department describe the manner of attack while still asking for help from anyone who might know what happened. In the information available from those releases, no suspect is publicly identified and no arrest or prosecution is described, leaving the case suspended in the same questions that hung in the air the afternoon her neighbors realized she hadn't come to the door. 
