David Mulcahay is a subject in the documentary 'The Railway Killers', suggesting he was involved in the crime as one of the perpetrators along with John Duffy.

David Mulcahay is a subject in the documentary 'The Railway Killers', suggesting he was involved in the crime as one of the perpetrators along with John Duffy.

Learn how two British school friends turned into cold-blooded killers. Subscribe to Our Life: https://bit.ly/3dBMxvl Serial killers are the dark stars of modern culture, but is it nature or nurture that creates a serial killer? Born To Kill takes an in-depth look at the cases of some of the most notorious murderers that have shocked the world. In the mid 80s, two British school chums - the short and introverted John Francis Duffy and the taller outgoing David Mulcahy - maintained their friendship and continued their shared interest in martial arts and serial rape into adulthood. Psychological Offender Profiling helps bring in one, while DNA testing eventually pulls in the other. Neither's individual interest in rape may have led to murder, but working together was another story, and the railway line became their hunting ground. This film was first broadcast: 2015 Watch More Documentaries Our Life - https://bit.ly/3A8xRMJ Our History - https://bit.ly/3rUpdhL Our World - https://bit.ly/3ftuckM Our Stories - https://bit.ly/3ynfFyk Our Taste - bit.ly/3OZoDcV Our Life brings you fascinating stories of social interest from around the world. You can discover award winning documentaries, films and groundbreaking reports that capture the complexities of our daily life, with stories that will entertain, inspire and inform. Content distributed by ITV Studios.