There is limited comprehensive research on serial killers, let alone comparing serial killers in two different countries. This leads us to question whether differences in countries may produce serial killers with similar characteristics or different patterns. This research paper involves a comprehensive secondary analysis of 10 United States and nine United Kingdom solo male serial killers during the 1980s. I studied these serial killers in four phases: (a) victim choice, (B) childhood abuse and mental health, (c) method, and (D) disposal site location. Future research based on these analyses can assist us in understanding how a country’s culture, society, geography, and demographics can have an influence on certain characteristics of a serial killer.