In 1986, Vic Vance was assassinated during a botched drug deal in Viceport Docks. Ever since his death, Docks has been reported by many users for Vic's ghost sightings. During many investigations, players discovered an unnatural and obscure glitch. Near his death site, many pedestrians gather in a circle, standing still and at times talking to an invisible entity. This has been assumed to be a "Circle of Death," as this could be a reference to the magic circle used by black magicians to form a defensive shield between the soul they summoned, and their physical self. This soul is said to be that of Vic Vance.
Along with these bizarre facts, the magic circle is used by many Wiccans, so it is possible that Gethsemanee Starhawk Moonwaker, Phil, and the Coven Witches are using their followers, the pedestrians in the area, to summon Vic Vance's ghost. Since Vic Vance was a criminal, this links it to the possibility of the witches using his soul for their dark gains.
However, despite many theories and possibilities about the Circle of Death, it can easily just be a glitch.