A documentary based on the doubles murders of Richard and Helen Thomas and Peter and Gwenda Dixon, The Pembrokeshire Murders: Catching the Gameshow Killer, looks at the crimes committed by John Cooper following the Luke Evans drama of the same name.
The serial killer had initially attempted to pass the blame onto his son, who was named Adrian at the time, after he was questioned about the crimes - but where is he now?
WATCH: Did you watch The Pembrokeshire Murders?
The writer of the ITV drama, Nick Stevens, opened up Adrian, who now goes by Andrew. He told ITV: "[Journalist] Jonathan Hill tracked Adrian down - although he no longer called himself Adrian; a name his father had given him - now, he was Andrew.
"Over the course of several meetings - quietly, frankly and without self-pity - Andrew told me how it had been for him growing up as the abused son of a serial killer... Thanks to Andrew's openness and generosity, the drama I was writing now had a poignant, deeply personal storyline which would run in parallel with the police procedural."
He is played by Oliver Ryan in the ITV show
Executive producer Simon Heath added: "We sought out John Cooper’s son, Andrew Cooper because his story is so much at the heart of the drama; we needed to be sure that he was comfortable with his story being told publicly."
While Andrew keeps his life very private, he was a witness for the prosecution at his father's trial back in 2011. At the time, he revealed that his father would keep hold of "other peoples' possessions" including photographs and jewellery.
Like this story? Sign up to our newsletter to get other stories like this delivered straight to your inbox.
