A man who did match the tall and blonde description was John Carr. Carr was literally the son of Sam Carr, Berkowitz's neighbour whose demonic dog apparently told him to murder his victims. Within his community, Sam actually had a reputation for being abusive to his sons John and Michael. In the Son of Sam letters sent to the police and the media, the writer notably addressed such abuse. But this wasn't where the John Carr connection ended.
When John went to Minot, ND after Berkowitz's arrest, he confessed to a mental health counselor about practicing witchcraft and being involved with Berkowitz, notably worried about getting in trouble in New York. In 1978, he died from a gunshot wound — police initially believed that his death was a suicide, but they now believe it was probably a homicide.
But who could be behind John's death? The evidence suggests that a cult member or cult members may have been responsible. From Terry's research, it appears as though John was part of a cult and was perhaps even a leader. When Terry looked at the path behind the Berkowitz and Carr residences, he discovered dead animals in addition to a blood-covered, ramshackle building locally known as the "Devil's Cave" — it was very feasible to suggest that this was a meeting place for Berkowitz and others.