Moore carried out her crimes through arsenic poisoning, a method that allowed deaths to appear natural and go undetected for years. The case drew particular attention because investigators ultimately suspected her first husband and her father may also have died under similar circumstances, raising the possibility of a pattern stretching back decades. Her story became a focal point for discussions about how domestic poisoners can operate invisibly within the structures of ordinary life.

Over the course of seven months in mid-1960s Katowice, Arnold killed four women and concealed their remains within his own apartment — a confined geography that ultimately led to his arrest when neighbors noticed the smell. His case is notable less for its scale than for its context: a pattern of escalating violence against women that had begun long before the murders, a confession offered without remorse, and a capture that turned on a routine street stop rather than any investigative breakthrough.