In 1973, Joseph Kappen murdered three teenage girls in quick succession - one in July, the other two on the same night in September. All three victims were raped and strangled. These shocking crimes cast a grim shadow over the Port Talbot area and over one man in particular. One of the girls had had sex with her boyfriend shortly before her death, and as there was no such thing as DNA profiling at that time, he remained a suspect albeit in a very general sense.
This documentary follows the police, one veteran detective in particular, after the murder investigation was re-opened with the advent of advanced DNA techniques. The police never close any murder inquiry totally if it remains unsolved, but even with something as heinous as this, resources have to be managed.
Although Kappen had an extensive criminal record, the police had no evidence that linked him to the crime, and his wife had given him an alibi at least once. The crime was solved by extracting DNA from the victims' surviving clothing, separating what was believed to be the killer's and comparing it with DNA in the police database. When there was no match, they went down the route of familial DNA, and that is the point of this documentary, namely this was the first time a serial killer had been traced by this method.
The final phase of the investigation involved exhuming Kappen and making the match. They did this in 2002, but he had died from natural causes in 1990 aged just 48.
DNA aside, if these crimes had been committed today, the police would almost certainly have brought him to book even without the now ubiquitous CCTV but because all the information on the murders would have been entered into various computers, and prosaic information overlooked at the time would have registered with detectives.
Kappen's "Wikipedia" entry suggests his reign of terror may not have stopped at three.
