Britain's longest serving murderer, John Massey, submits himself to a ground-breaking biological and psychological investigation to determine whether he truly had control over his actions Three convicted murderers submit themselves to a ground-breaking biological and psychological investigation to determine whether they truly had control over their actions, or if hidden factors destined them to kill. The investigation could have huge implications in how society treats its ultimate offenders, and how the fundamentals of crime and punishment function. Subscribe here for more true crime documentaries: https://www.youtube.com/channel/UC_0r3EheCnp-wVvndYDGviQ?sub_confirmation=1
