Steeltown Murders: is it a true story? Who is the serial killer? And where are the detectives now?

Steeltown Murders key art
(Image credit: BBC/Seven Film/Tom Jackson)

There's no doubt that true crime dramas are popular on TV right now. But Steeltown Murders on BBC One is a little bit different, as it focuses on the cops at the centre of the remarkable 30-year hunt to catch Wales’s first serial killer, known as the Saturday Night Strangler.

Starring Philip Glenister from Life on Mars fame as DCI Paul Bethell, and Gavin & Stacey's Steffan Rhodri as Phil ‘Bach’ Rees, the story follows two timelines, the early 1970s and early 2000s, as the detectives hunt the murderer of three teenage girls before finally solving the mystery after three decades using pioneering DNA evidence.

But how much of Steeltown Murders actually happened? Here’s everything you need to know…

Is Steeltown Murders based on a true story?

Yes. Steeltown Murders centres on the real-life hunt to catch the killer of three young women in the Port Talbot area of South Wales in 1973, and how the mystery was solved almost 30 years later using pioneering DNA profiling.

The so-called "Saturday Night Strangler" killed three 16-year-old girls within six weeks. For decades, the murders of Geraldine Hughes, Pauline Floyd, and Sandra Newton remained unsolved, despite hundreds of officers being involved in the investigation.

It was only when a small team of detectives, led by DCI Paul Bethell and Phil Rees, reopened the case in 2000 that the killer was posthumously identified via groundbreaking familial DNA profiling.

Who were the victims in the Steeltown Murders case and what happened? 

The bodies of 16-year-old factory workers Geraldine Hughes and Pauline Floyd were found dumped in woodland near Swansea on September 16, 1973, sparking the biggest manhunt South Wales police had ever seen. The night before the two friends had left the Top Rank nightclub in Swansea, but they never made it home.

Just six weeks earlier another 16-year-old, Sandra Newton, had also been found dead in a ditch after trying to hitchhike home following a night out. All three had been sexually assaulted and strangled, leading to fears that a serial killer was on the loose.

At the time, witnesses saw Geraldine and Pauline getting into a white Austin 1100. One suspect soon came to detectives’ attention: local man, Joseph Kappen. But he claimed his own white Austin 1100 had broken down and that he’d spend the night watching TV with his wife.

Despite 150 officers being involved in the investigation that saw hundreds of men from the nearby Port Talbot steelworks interviewed, the case eventually went cold.

DCI Paul Bethell (Scott Arthur) stood in front of a blue car in Steeltown Murders

DCI Paul Bethell (Scott Arthur). (Image credit: BBC/Severn Screen/Tom Jackson)

How did detectives eventually catch the Steeltown Murders killer? 

By 2000, advances in DNA profiling meant investigators could now extract DNA from the victims’ clothing and could start searching the national DNA database.

The case was reopened under the name Operation Magnum, headed up by DCI Paul Bethell and Phil Rees. Although no exact match was found for the killer, detectives decided to search for a 50% DNA match with a possible relative. 

They struck lucky as one man — Paul Kappen — fit the profile, and he had a familiar surname! Although Paul Kappen was only seven at the time of the murders, his father, Joseph Kappen, had initially been quizzed by detectives but had somehow slipped under the radar, despite driving the same model of car spotted on the night in question.

Unfortunately, Joseph Kappen had already died of lung cancer in 1990. But in 2002 the exhumation of his body began, with DNA taken from his femur and teeth, which proved a full match. After 29 years the girls’ killer had been caught, albeit from beyond the grave.

Who was Steeltown Murders killer Joseph Kappen? 

Joseph Kappen was a nightclub bouncer from Port Talbot, known as a habitual petty criminal with a violent temper. Aged 31 at the time of his crimes, he died in 1990 from lung cancer. 

He remains notable for being the first person ever to be posthumously identified as a serial killer via familial DNA profiling. He was also the first documented serial killer in Welsh history. 

Where was Steeltown Murders filmed?

The series was filmed in and around the real areas where the crimes took place, including Port Talbot, Burry Port, Llandarcy and the Neath Valley. 

Some well-known South Wales landmarks can also be seen in the drama, such as the Kardomah Café in Swansea, the Naval Club in Sandfields and The Royal British Legion Club in Port Talbot.

What happened to the real-life detectives in the Steeltown Murders case? 

Steeltown Murders

(Image credit: BBC)

Both Paul Bethell and Phil Rees (played by Philip Glenister and Steffan Rhodri) worked with the writers and creators of the Steeltown Murders drama to provide information and guidance, meaning the series sticks closely to what actually happened.

"This case would go down in global criminal history for the revolutionary methods used by the South Wales Police," explains DCI Bethell, who’s now retired. "It was a massive moment for us as investigators."

Where can I watch Steeltown Murders?

The four-part series begins on Monday, May 15 at 9 pm on BBC One, with new episodes on subsequent Mondays. The entire four-part series will be available as a box set on BBC iPlayer after the first episode airs.  

Hannah Davies

Hannah has been writing about TV for national newspapers and magazines ever since the 1990s when she covered the soaps for Woman magazine — and she still prides herself on rarely having missed an episode of EastEnders. Since then she’s written for various publications, including What To Watch, TV Times, What’s On TV, TV & Satellite Week, Woman & Home, Psychologies and Good Housekeeping

Apart from EastEnders, her other favorite shows include Succession, Unforgotten, Line of Duty, Motherland and anything by Russell T Davies. When Hannah isn’t watching or writing about telly, you’re likely to find her enjoying London’s latest theatre shows, taking her campervan on a wet UK holiday or embarrassing her teenage kids.