Over a span of sixteen years, McGregor carried out a series of sexual assaults and killings in the Greater Houston area, targeting four women while maintaining the appearance of ordinary working life as a delivery driver. The prolonged timeline — stretching from 1990 to 2006 — reflects both the difficulty authorities faced in connecting the crimes and the sustained nature of the violence involved.

As head of the NKVD during some of the Soviet Union's most violent years, he commanded the machinery of state terror with unusual administrative competence — organizing mass executions, deportations, and purges on a scale that shaped the fate of millions across Eastern Europe and the Soviet interior. His longevity at the apex of the security apparatus, outlasting rivals who were themselves consumed by the system, speaks to a particular talent for navigating — and perpetuating — structures of extreme institutional violence. The Katyn massacre alone, which he personally ordered, became one of the defining atrocities of the Second World War era.