Channel 4's true crime documentary series 999: What Happened Next has returned with a chilling episode that exposes voice recordings from a killer who idolised the fictional serial killer Dexter. The recordings were so horrifying they had to be "locked away" from all but a small number of people.
The episode, which aired on September 28 at 9pm, focuses on a North Wales murder investigation after the body of a woman was found brutally attacked in a local nature reserve.
Body found in nature reserve
45-year-old Angela Shellis was found in the undergrowth by a member of the public in October 2025 in the Morfa Nature Park. Detectives investigating the case soon uncovered a dark reality when the evidence pointed towards her own son Tristan Roberts.
It was heard how Tristan had attacked his mum before keeping her hostage for several hours before leading her to the nature park during the early hours of the morning to kill her in what was described as a "frenzied attack".
Disturbing Dictaphone evidence
A synopsis reads: "When a body is discovered brutally murdered in a remote nature reserve in North Wales, detectives begin a complex investigation to uncover how she came to be there."
"They quickly identified the victim as a 45-year-old woman who had been reported missing from her family home. Officers piece together her final movements and examine those closest to her."
The episode hears directly from the officers involved in the case as they discuss one particular disturbing piece of evidence, which was a Dictaphone.
DC Phil Williams said in the episode: "In this particular case what was on the Dictaphone was horrifying. He introduced himself to the Dictaphone, he said words to the effect of my name is Alex not Tristan Roberts and tonight I'm going to murder my mother with a sledgehammer."
Recordings locked away
Viewers heard how the recordings suggested Angela had been "fearful" and "pleading for help" before Tristan told her he would get her medical attention.
Claire Owen, of North Wales Police, admitted: "It's absolutely horrendous I can't think of a strong enough word. We've had to basically lock the audio down so that it couldn't be heard by anyone outside of a very small number of people because it was so upsetting and so revolting."
Amongst the evidence found, it was also discovered that Tristan had a "very vocal hatred towards his mother", as well as all females. DC Phil Williams added that he had a particular interest in two fictional serial killers. He said: "One was the character Dexter who was a serial killer."
Tristan Roberts almost idolised him and the other person he was obsessed with was Patrick Bateman, the serial killer in the notorious film American Psycho.
One of the screenshots from the laptop shows a chilling message that read: "idk i like him haha dexter hes like me but I wanted peace you know? and i'll kill anyone who tries to take it from me."
The chilling episode can be streamed on Channel 4 online, as well as other episodes from the series.
