According to The Shadow, the personal ad read “friend seeking friend” to “share activities” like photography, music, and the beach. Police surmise that Kristen Modafferi either placed the ad or answered it. In addition, they believed the blond woman who was last seen with her was connected to the ad, but she has never been found. A few weeks after her disappearance, Unsolved Mysteries Wiki reports that a man named Jon Onuma called the ABC 7 news station and said that Modafferi had been killed by two women he knew.

Per The Charley Project, the women were questioned and told investigators that Onuma had harassed them due to a “work-related incident” involving his girlfriend, Jill Lampo. He then admitted he had made the phone calls to “cause problems” for the women. When investigators looked into Onuma, they found he had a history of abusing women and using personal ads. Furthermore, a search of his home led them to Lampo’s diary. Pages from the time Modafferi had disappeared were torn out. Despite this, Unsolved Mysteries writes that there was no “clear evidence” to connect him to her disappearance.

A 2015 investigation of Modaferri’s Oakland basement detected “human decomposition” (via ABC 7). It’s theorized that she had been killed there, and her body was transported elsewhere. As of 2022, the case remains unsolved, as Modafferi has never been found. Her father has stated that he believes Onuma and Lampo are “hiding something.”