Pair convicted of manslaughter and poisoning after death of Banbury man Gary Mouat
A man and woman have been convicted of manslaughter following the death of Banbury man Gary Mouat last year.
Madalin Dumitru, 30, and Adina Mihai, 31, have pleaded guilty to the manslaughter of 37-year-old Gary Mouat at his home in Hazeldene Gardens on July 13, 2025.
The pair, formerly of Ilford, Essex, also admitted the manslaughter of 80-year-old Malcolm King from Bagendon, Gloucestershire, on August 21, 2024.
They both pleaded guilty to two counts of manslaughter and two further poisoning charges at the start of their trial at Oxford Crown Court on Wednesday, June 24.
The further poisoning counts relate to two surviving victims, who cannot be identified due to reporting restrictions.
Between August 2024 and July 2025, the couple targeted men seeking sexual services online.
They took financial deposits before Mihai visited the victims at their homes.
At the properties, Mihai spiked drinks with GBL (Gamma-Butyrolactone) — a substance which converts into GHB (Gamma-Hydroxybutyrate) in the body — to make the victims unconscious.
Once unconscious, Mihai stole cash and jewellery.
After Thames Valley Police discovered Mr Mouat had been poisoned, it issued a national bulletin to all police forces to share intelligence in case of linked unexplained deaths.
This led Gloucestershire Constabulary to reopen its investigation into Mr King, after initially believing his death was not suspicious due to pre-existing health conditions.
The pair were arrested on July 31 last year and charged on August 6 in connection with Mr Mouat’s death, with further charges brought on April 24 this year relating to Mr King.
They are due to be sentenced later this year. The judge has said they will receive “substantial terms of imprisonment”.
Thames Valley Police senior investigating officer Detective Inspector Michael Roddy said the investigation had been “extremely complex and resource-intensive”, involving teams across both forces and partner agencies.
He said: “Adina Mihai and Madalin Dumitru used drugs to incapacitate men who had been seeking sexual services, before stealing from them.
“For Gary Mouat, these actions had fatal consequences, so I am pleased to have got answers for his family and would like to thank them for their support throughout our investigation.”
Presently no other deaths, poisonings or thefts are linked to the investigation, although police are keeping an open mind about other possible victims.