Emma Barnett murdered her 14-month-old son Oakley with a fatal cocktail of prescription medication she mixed into his milk, hours after a family court ruled he should be taken into care.
The 36-year-old mother was found guilty of murder on 28 May after an 18-day trial at Cambridge Crown Court. Judge Mr Justice Derek Sweeting presided over the case.
Hiding from authorities
On 8 November 2024, following a family court hearing that determined Oakley should be removed from the household, Barnett hid with her son in the loft of her home in Debden, Essex. In an attempt to mislead police, she drove her car to Epping Forest and walked back home.
Barnett and Oakley were initially reported missing, with early suggestions they had gone to the forest. Officers forced entry to Barnett’s home and discovered the pair in the loft. The judge later told the court that Barnett had said in interview she “wanted the police to think I was in the forest so I could stay indoors with Oakley”. He added that she “hid in the loft with Oakley” and initially refused to allow police to see him.
Social workers had been trying to locate Barnett and safeguard Oakley that day, the judge said, and “the intention was to remove Oakley as that was the result of the court hearing”.
A fatal mixture of medications
The Crown Prosecution Service said evidence presented at trial showed Barnett had prepared a bottle containing a mixture of milk and medication, which she gave to Oakley, causing his death. Investigators found two baby bottles in the loft; liquids from both tested positive for the antihistamine promethazine, which can induce sedation, and the antidepressant mirtazapine.
An expert witness told the court that taken together, the effects of promethazine and mirtazapine “may be greater than either alone” and could cause “respiratory compromise”. Medical literature notes that combining the two drugs can increase side effects such as dizziness, drowsiness, confusion and difficulty concentrating. There is also a potential risk of QT prolongation and serious cardiac events, as well as serotonin syndrome, particularly in overdose.
When police first spoke to Barnett by phone and through the loft hatch, she initially told them Oakley was sleeping. She later admitted, “I have killed him.”
The prosecution case, the judge summarised, was that Barnett “intentionally administered to him medication prescribed to her intending to kill him and this was the planned outcome”. Barnett’s defence argued the death was accidental, that she did not intend serious harm or to kill her son, and that her intention was to take her own life only at the point Oakley would be removed from her by police. Hiding in the loft, the defence said, was to extend the time she had left with Oakley.
The judge further noted that Barnett tried to hang herself in the presence of police and had taken an overdose of paracetamol. She was later treated in hospital, arrested on suspicion of murder in January 2025, and charged in June 2025 after refusing to answer questions during an interview.
Oakley was taken to hospital and died on New Year’s Eve 2024.
Nicola Pope, senior Crown prosecutor for the CPS, said: “Emma Barnett deliberately gave her baby son a dangerous mixture containing medication which proved fatal. Our prosecution case relied on a detailed and careful analysis of the evidence from the police investigation, including expert medical evidence, to establish how Oakley came to die. I hope that today’s outcome provides some measure of peace to Oakley’s family and loved ones during this deeply upsetting time.”
Detective Inspector James Holmes of Essex Police said: “This was an extremely upsetting and difficult investigation for everybody involved. Our thoughts remain with Oakley and everyone who loved him.”
Barnett is due to be sentenced at Cambridge Crown Court on 5 June 2026.
