Watch Making A Monster

The final episode looks at a man who took the lives of at least eight victims and became the last person to receive the death penalty in Connecticut.

Dr Richard Rappaport (psychiatrist) spent 66 hours interviewing John Wayne Gacy, who murdered 33 young men. Dr Rappaport's psychiatric assessment is widely considered to be one of the most important ever made about a serial killer.

Dr Jethro Toomer (forensic psychologist) did the original psychological assessment of Aileen Wuonros after she confessed to the murders of 7 men. He reveals the shocking details of her upbringing that sowed the seeds of her destruction as a human being and led to the construction of her as a serial killer. One of Dr Toomers previous patients was serial killer Ted Bundy.

Stephen Griffiths: A look into the mind of media-savvy serial killer who took the lives of three sex workers in his sickening quest for infamy.

Dr Richard Baddcock (psychiatrist) gives his first ever interview about his patient Robert Black, who was the most prolific child murderer the UK has ever seen.

Levi Bellfield: A deep dive into the mind and motives of the serial killer, known for his brutal slayings of random, innocent women.

Robert Maudsley: He took the lives of three men while serving a life sentence for killing the fourth. His rationale? Avenging his own abusive childhood experiences.

Rose West: An analysis of the convicted killer, who took 10 lives over 16 years - including a look at her own troubling childhood and how it may have influenced her crimes.