Sign inOpen the app
Artwork for Three doors down
True Crime

Three doors down

Tortoise Media

Full series out now


Three doors down: a murder, a mother and a thirty year investigation


In May 2023 David Boyd was found guilty of the brutal murder in 1992 of seven year-old Nikki Allan. Sharon Henderson, Nikki’s mother, called for a public inquiry into why it had taken the police so long to find and convict her daughter’s murderer. 


When Nikki was murdered, Sharon was a single mother of four living in Wear Garth, a rundown housing estate in Sunderland. David Boyd lived a few floors above Sharon in the same block. He was known to the police. He was the kind of offender who should have been caught. 


Three doors down tells the astonishing story of Sharon Henderson’s thirty year campaign to get justice for her daughter’s killing. It shines a light on police behaviour and their treatment of working class women. It’s a personal tale of trauma and resilience in the face of systemic police failure, that couldn’t be more timely. 


For the premium Tortoise listening experience, curated by our journalists, download the free Tortoise audio app. For early and ad-free access to Tortoise podcasts, subscribe to Tortoise+ on Apple Podcasts.


If you’d like to further support slow journalism and help us build a different kind of newsroom, do consider donating to Tortoise at tortoisemedia.com/support-us. Your contributions allow us to investigate, campaign and explore, and to build a newsroom that is responsible and sustainable.

Hosted on Acast. See acast.com/privacy for more information.

SubscribeListen in podnodRSS feedShow website
  • 9 episodes
  • Updated Jul 22, 2025
  • Explicit

Episodes9

Newest first
  • Jul 22, 2025 · 40 min

    Introducing...The Lab Detective

    Introducing...The Lab Detective Kathleen Folbigg was known as ‘Australia's worst female serial killer’ - she’d lost all four of her infant children and was convicted for killing them. Until, after spending decades in jail, a scientist working in a lab uncovered the truth behind the deaths. The Lab detective is the story of a shocking miscarriage of justice, and an investigation into why Kathleen’s story might not be the last. This is episode one of four. You can listen to the entire series today by subscribing to The Observer+ on Apple Podcasts or Spotify or by downloading the Tortoise app. To listen, search for The Lab Detective wherever you get your podcasts. To find out more about The Observer: Subscribe to TheObserver+ on Apple Podcasts for early access and ad-free episodes. Head to our website observer.co.uk Download the Tortoise app – for a listening experience curated by our journalists Reporter: Rachel Sylvester Producer: Gary Marshall Music supervisor: Karla Patella Sound design: Rowan Bishop Podcast artwork: Lola Williams Executive producer: Basia Cummings Hosted on Acast. See acast.com/privacy for more information.

  • Jul 9, 2024 · 41 min

    Introducing...Dangerous Memories

    Introducing...Dangerous Memories When Sarah watched her 23 year old daughter cycle away from her in Chelsea - a well-off corner of London - she had no idea it would be the last time they’d see each other for 6 years. What would make a loving child from a life of privilege sever ties with friends and family, and disappear? It turns out, Sarah wasn’t alone in losing a daughter. Something strange was happening to other young women, too. And they all had one thing in common: a kind of therapist figure - a woman they were all seeing and sharing their problems, their secrets, their fears with. But it took years for the truth of what was happening behind closed doors to emerge, and the extraordinary things this woman led them to believe. Dangerous Memories is the story of young women who wanted to be healed that became, for us, a story about the healer, and what we risk when we let someone else into our mind, and our memory. The first 2 episodes are out now and released weekly. To binge-listen to all 6 episodes ad-free from today, subscribe to Tortoise+ or download the Tortoise app To find out more about Tortoise: Download the Tortoise app - for a listening experience curated by our journalists Subscribe to Tortoise+ on Apple Podcasts for early access and ad-free content Become a member and get access to all of Tortoise's premium audio offerings and more If you want to get in touch with us directly about a story, or tell us more about the stories you want to hear about contact hello@tortoisemedia.com Reporter: Grace Hughes-Hallett Producer: Gary Marshall Additional reporting and production: Imogen Harper Sound design and original composition: Tom Kinsella Theme music: Far Gone (Don’t Leave) by Pictish Trail Podcast artwork: Lola Williams Commissioning editor: Basia Cummings Executive producer: Ceri Thomas Hosted on Acast. See acast.com/privacy for more information.

  • Aug 8, 2023 · 21 min

    Inquiry | Ep 5

    The police say they are not looking for any more victims of David Boyd but we met other women who were confronted by the killer.

  • Aug 1, 2023 · 23 min

    Conviction | Ep 4

    Sharon's case should be extraordinary but it isn't. A few miles away from Sharon another mother was left to solve her own daughter's murder

  • Jul 25, 2023 · 29 min

    Confession | Ep 3

    The number one suspect is interrogated by police until he confesses but it's not until 30 years later that the right man is put on trial.

  • Jul 18, 2023 · 30 min

    Rumours | Ep 2

    Rumours choke the case and a vulnerable suspect is arrested. The first 48 hours after a crime are crucial: what did the police get so wrong in the days after Nikki went missing?

  • Jul 18, 2023 · 24 min

    Missing | Ep 1

    In 1992 on a council estate in Sunderland a seven year old girl is murdered. It took the police 30 years to find the killer, a convicted child sex offender who lived three doors away from where Nikki Allan went missing.