Sophie Lionnet was from Troyes, a quiet town in northeastern France.

She was shy, gentle, and had a love of children and cinema.

Came to London in early 2016 to work as an au pair and improve her English.

Employed by Sabrina Kouider and Ouissem Medouni to care for their two children.

Sophie was paid just £50 a month — far below legal or ethical standards.

She had no employment contract, and her passport and phone were taken.

Neighbours and local shopkeepers observed she was thin, withdrawn, and appeared malnourished.

A local chip shop owner recalled Sophie saying quietly, “They beat me at home.”

Sabrina Kouider was obsessed with her ex-boyfriend, Mark Walton, a founding member of Boyzone turned music executive.

She developed an unfounded belief that Walton was spying on her, hacking her devices, and plotting against her and her children.

She believed Sophie had been recruited by Walton to act as a spy and to drug the family.

These delusions were shared with and absorbed by Medouni — a classic example of folie à deux (shared psychosis).

In July 2017, Sophie briefly escaped and stayed with a friend, saying she was unhappy.

Kouider persuaded her to return with promises of payment and letting her return to France.

Once back in the home, Sophie was subjected to twelve days of escalating abuse.

Sophie was:

• Interrogated for hours on end.

• Starved and sleep-deprived.

• Drowned repeatedly in the bath (a form of water torture).

• Beaten with electrical cords.

• Forced to record “confessions” stating she worked for Walton.

Medouni often went for walks when the abuse got “too much”, but never sought help.

ophie likely died on 18 or 19 September 2017, either from drowning, blunt force trauma, or cumulative abuse.

Kouider and Medouni placed her body on a bonfire in the garden and set it alight.

When neighbours questioned the smell, they claimed they were “roasting a sheep.”

A neighbour called the fire brigade, and firefighters discovered Sophie’s remains on 20 September 2017.

Kouider and Medouni were arrested quickly.

Investigators found:

• Over 8 hours of video footage of Sophie’s forced “confessions.”

• Evidence of torture and restraint.

• Delusional writings and recordings linking back to Walton.

Sophie’s body was too badly burned to confirm exact cause of death, but autopsy revealed multiple rib fractures and internal injuries.

Trial began March 2018 at the Old Bailey.

Both defendants admitted to burning the body but blamed each other for the murder.

Mark Walton flew in from LA to testify, confirming he had never met Sophie.

Prosecutors described it as a case of “deluded cruelty and sustained torture.”

Judge Nicholas Hilliard QC said:

“This was a murder which involved deliberate, sustained and increasingly cruel behaviour… prolonged torture carried out with chilling determination.”

In May 2018, both Kouider and Medouni were found guilty of murder.

In June 2018, they were sentenced to life in prison, with a minimum term of 30 years.