A mother who poisoned her one-year-old son with a lethal cocktail of prescription medications added to milk in a baby bottle has been jailed for life for his murder.

Emma Barnett, 36, killed her son Oakley before he could be taken into care after a family court hearing ordered that he be removed from her.

The judge, Mr Justice Derek Sweeting, told Cambridge crown court that Barnett had arranged to join a family court hearing remotely on 8 November 2024.

He said that before the hearing started she drove her car to Epping Forest, and collected medications that had been prescribed to her on the way home.

Barnett, of Debden, Essex, laid a false trail, creating the impression she had gone to a friend’s house and later to Epping Forest, when in fact she was hiding in the loft at her address with her son.

She added the antihistamine promethazine, which can induce sedation, and the antidepressant mirtazapine to juice and milk in Oakley’s baby bottles.

The judge said that after the family court hearing that ordered Oakley’s removal, social workers and police sought to find Barnett to remove the toddler.

“As the evening progressed concern grew for your welfare and Oakley’s safety,” the judge said. He said Barnett’s car was found in Epping Forest, leading to a search with a helicopter and police dogs.

Police attended her address shortly before midnight and “heard the sound of a baby crying coming from the loft”, the judge said.

He said an officer tried to talk her down but at 12.16am on 9 November “the situation changed dramatically – in answer to a question from a police officer, you said ‘I killed him’”.

The judge said officers “immediately forced entry” and found Oakley unresponsive and that Barnett had tried to take her own life.

Oakley, who was 14 months old, died in hospital on 31 December 2024.

The judge, sentencing Barnett to life in prison with a minimum term of 22 years on Friday, said: “This was the killing of a very young and vulnerable child wholly dependent on you brought about by your deliberate actions.”

He said he was “certain” Barnett had “set about planning (her) own death in advance”.

The judge added: “I consider it at least possible it wasn’t until 8 November you came to the view that if you could not have Oakley, no one else could have him.”

The judge acknowledged she had a “recognised mental health disorder”, and that her five older children had already been removed from her care.

Jonathan Higgs KC, mitigating, said the five children were removed “as she was unable to look after them herself”. He said she was of previous good character.

Barnett had denied murder but was found guilty last week after an earlier trial.