His leadership of the Casalesi clan placed him at the center of one of Italy's most powerful and violent Camorra factions, an organization with deep roots in the Caserta region and a reach extending into construction, waste disposal, and drug trafficking. The clan's operations under his direction became a subject of sustained judicial and journalistic scrutiny, most notably through Roberto Saviano's work on the Camorra.

Glenn's case centers on one of the more legally contested questions in American criminal justice: the degree to which presence and participation in a crime spree constitutes culpability for its worst acts. The 1975 murders in Colorado Springs, carried out over a short period by Glenn and two accomplices, included the killing of Karen Grammer — a crime that would later become publicly known partly through its connection to her brother, the actor Kelsey Grammer. Glenn has spent decades in prison maintaining that his role was peripheral, a claim that gained some posthumous support from co-defendant Michael Corbett before Corbett's death in 2019.

Operating without a fixed residence in Brooklyn during 1999 and 2000, Johnson killed five women across Williamsburg and Bedford-Stuyvesant, leaving their bodies in rooftops, vacant lots, and utility spaces with little apparent attempt at concealment. He was identified through an informal tip network among the homeless community and ultimately caught via a DNA sample retrieved from his own discarded saliva. His confession revealed a pattern shaped by deliberate fixation — targeting victims on a specific day of the week for reasons rooted in his relationship with his mother — suggesting a structured internal logic behind crimes that might otherwise have appeared opportunistic.

A Texas saloonkeeper whose precise body count has never been established, Ball drew suspicion through a pattern of missing women — mostly barmaids in his employ — and evaded formal questioning by shooting himself as deputies arrived. Two confirmed killings were documented through a conspirator's testimony, but the true number remains uncertain, obscured by limited contemporaneous records and Ball's death before he could be charged. The alligator pond he maintained as a public attraction added a layer of macabre theater to a case that has never been fully resolved.

The Unification Church he built became one of the most scrutinized new religious movements of the twentieth century, attracting both devoted followers by the millions and persistent allegations of coercive recruitment, financial exploitation, and authoritarian control over members' personal lives. His organization accumulated vast business holdings and exerted influence across conservative political networks in the United States, South Korea, and beyond — complicating any straightforward categorization of his legacy as purely religious.