How a Welsh Serial Killer Was Caught Decades Later

The 2021 documentary series 'Murders on the Coastal Path' (known in Danish as 'Drabene på kyststien') represents a significant entry in the international canon of cold case television, exploring how law enforcement can resurrect decades-old homicides through determination and forensic innovation.

The story centers on John Cooper, a serial predator who terrorized the rural communities of Pembrokeshire, Wales, with a series of brutal attacks spanning multiple years. Two particularly horrifying double murders—one in 1985 and another in 1989—remained officially unsolved for years, their files gathering dust in police archives. For the families of the victims and the isolated coastal communities where the crimes occurred, the cases represented a failure of justice that seemed permanent.

The series, created by directors Marc Evans and Nick Stevens, follows Detective Chief Superintendent Steve Wilkins as he undertakes the difficult work of reopening these cold cases. Wilkins became obsessed with finding answers where previous generations of investigators had encountered dead ends. His determination forms the emotional core of the three-episode narrative, illustrating the personal toll that unsolved crimes exact on investigators as well as victims' families.

What makes this documentary particularly noteworthy for international audiences is its methodical approach to case reconstruction. Rather than relying solely on dramatic reenactments, the series demonstrates how physical evidence—particularly blood samples—provided crucial links to Cooper's crimes. The combination of traditional forensic investigation with emerging DNA technology proved decisive in building a case that could survive scrutiny decades after the original offenses.