
Volume 15 · Chapter 8
The French Nanny
Sabrina Kouider, Ouissem “Sam” Medouni
Victim: Sophie Lionnet
Case at a glance
- When
- August to September 2017
- Where
- Southfields, near Wimbledon, southwest London, England
- Perpetrator
- Sabrina Kouider and Ouissem “Sam” Medouni
- Victim
- Sophie Lionnet
- Outcome
- Both convicted of murder in May 2018 and sentenced to life with a minimum of 30 years; appeals dismissed in July 2019
The case
Sophie Lionnet grew up in Troyes, in northeastern France. In 2016 she moved to London to work as an au pair for Sabrina Kouider and her partner, Ouissem “Sam” Medouni, caring for Kouider’s children at their home in Southfields, near Wimbledon. The couple paid her very little and took her passport, leaving her with almost no way to leave.
Kouider had once dated Mark Walton, a former member of the Irish band Boyzone, and she became convinced that Sophie was part of a plot involving him. From August 2017 the couple questioned Sophie for weeks and recorded the sessions. They beat her, starved her and forced her head under water. The last recording of Sophie alive was made shortly before midnight on September 18, 2017. She died in the bathtub. She was 21.
On September 20, neighbors noticed smoke from a bonfire in the back garden. Firefighters found human remains in it, and both Kouider and Medouni later admitted burning Sophie’s body. On May 24, 2018, a jury at the Old Bailey convicted them of her murder. On June 26, 2018, each was sentenced to life in prison with a minimum term of 30 years. In July 2019 the Court of Appeal dismissed their appeals against both the convictions and the sentences.
Read the full story
This case is told in full in True Crime Case Histories, Volume 15 by Jason Neal.
Get Volume 15 on AmazonCase photographs
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Where it happened
Why this case
“The recordings are the detail I can’t set aside. Kouider and Medouni documented their questions as if building a case, when the only real case was against them. Sophie was far from home, without passport or money. Local shopkeepers saw her waste away, and police met her weeks before she died, yet nobody grasped her danger.”
— Jason Neal, author of True Crime Case Histories










