The Psychology of a Gangland Execution: Inside the St. Valentine’s Day Massacre

What psychological processes allow multiple offenders to participate in a coordinated mass killing? Using the St. Valentine’s Day Massacre as a historical case study, we examine group loyalty, moral disengagement, instrumental aggression, and the diffusion of responsibility. Rather than diagnosing unknown perpetrators, this episode explores established forensic psychological concepts that help explain how organized criminal violence can become deliberate, calculated, and emotionally detached.