He scored 39 out of 40 on the Hare Psychopathy Checklist. He gave over 200 hours of interviews to the FBI. Scientists removed his brain after execution and found nothing abnormal. The final installment of The Crime Ledger's criminal analysis examines what the clinicians found, what the confessions revealed, and how one case built the infrastructure of modern American criminal justice.

What drives criminal behaviour? The Crime Ledger examines key criminology theories — from strain theory to biosocial models — to understand how psychology, environment, and social structures shape crime.