Key Points
- A man and a woman have admitted manslaughter over the death of Banbury man Gary Mouat and an older man from Gloucestershire.
- The pair, named in reports as Adina Mihai and Madalin Dumitru, also admitted administering poison in two other incidents involving surviving victims.
- Reports say the poison used was GBL, described in coverage as a date-rape drug with sedative effects.
- Thames Valley Police concluded after a postmortem that Gary Mouat was poisoned by GBL added to an alcoholic drink.
- The case was heard at Oxford Crown Court, where the defendants changed their pleas and are now awaiting sentencing.
- Reporting states the judge indicated that long prison sentences are likely.
Banbury (Oxford Daily) June 24, 2026 – A man and a woman have been convicted after a poisoning case linked to the death of uk/local/banbury/">Banbury resident Gary Mouat, with reports stating the court heard pleas to manslaughter and administering poison.
What happened in court?
As reported in the available coverage, the case centred on the death of Gary Mouat, who died after being poisoned with GBL, according to investigators and court reporting. The court also heard that another victim, Malcolm King from Gloucestershire, died in a separate but related incident. Reports say the defendants admitted manslaughter and additional poison charges at Oxford Crown Court.
Who are the defendants?
Media reports identify the pair as Adina Mihai and Madalin Dumitru. The coverage says both were accused of using poison in order to steal from victims, with reporting describing Mihai as posing as a sex worker while the pair targeted men. The reports also say the defendants are now in custody pending sentence.
How was Gary Mouat killed?
The reports say Thames Valley Police concluded that GBL was added to Mr Mouat’s alcoholic drink, leading to his death. GBL is described in the coverage as a sedative that can metabolise into GHB in the body. The case forms part of a wider pattern of alleged poisonings involving at least two other surviving men.
What charges were involved?
Coverage says the pair admitted two counts of manslaughter and two counts of administering poison with intent to injure, aggrieve or annoy. Earlier reporting also noted murder allegations and a longer list of charges before the pleas changed. The court is expected to move next to sentencing, with the judge reportedly warning of severe custodial terms.
Why does this case matter?
This case has drawn attention because it combines poisoning, robbery allegations, and multiple victims across different counties. For Banbury, the death of Gary Mouat has become the most prominent local link to the wider prosecution. The case also shows how police and courts can connect apparently separate deaths and assaults into one investigation.
Background of the development
The investigation appears to have developed over many months, with police first treating parts of the case as unexplained death and later linking the incidents through forensic work and witness evidence. Earlier reports said the pair had denied charges in April 2026 before later changing their pleas at Oxford Crown Court. The naming of Gary Mouat in the court reporting follows the progress of the case from police inquiry to formal prosecution.
Prediction
For Banbury residents and Mouat’s local community, the sentencing stage is likely to provide the clearest legal conclusion and may renew discussion about personal safety and vulnerable-target crime. For wider audiences, the case may strengthen scrutiny of drug-facilitated theft cases and prompt continued interest in how police join together related poisonings across different areas.
