A mother-of-six who fed her baby a 'lethal cocktail' of drugs after he was ordered to be taken into care has been jailed for 21 years.Emma Barnett, 36, was unanimously convicted of killing her one-year-old son Oakley after poisoning the tot with prescription medications in December 2024.Barnett, of Loughton in Essex, was jailed for life for the murder and handed a minimum term of 21 years and 7 days following a trial at Cambridge Crown Court.Mr Justice Derek Sweeting, presiding, said Barnett had arranged to remotely join a family court hearing on November 8, 2024, where Oakley's removal from her care was ordered. She already had her five older children taken away by the authorities when she learned Oakley was to be removed too. However, before the hearing could begin, the court heard Barnett drove her car to Epping Forest and then collected prescription medications on her way home. She then created a red herring by claiming to have visited a friend's house and then went to Epping Forest, when in fact, she was hiding in the loft of her address with her 14-month-old son. While hiding, Barnett proceeded to add the antihistamine promethazine, which can induce sedation, and the antidepressant mirtazapine to juice and milk in Oakley's baby bottles. Emma Barnett has been jailed for 21 years after poisoning her son with prescription medicationsJudge Sweeting said following the family court hearing ordering Oakley's removal, social workers and police sought to find and take him.But as the evening progressed, he said, 'concern grew for your welfare and Oakley's safety.'Judge Sweeting said Barnett's car was later found at Epping Forest, leading to a search with a helicopter and police dogs.Police then attended her address shortly before midnight, where 'the sound of a baby crying coming from the loft' was heard.The court heard an officer tried to talk Barnett down, but at 12.16am the situation 'changed dramatically' after she was given the option of allowing a camera in or a forced entry would be made.Judge Sweeting said: 'In answer to a question from a police officer you said 'I killed him'.'He said officers 'immediately forced entry,' and found Oakley unresponsive. Officers also found Barnett had attempted to end her life. Oakley, 14 months, was fed a 'lethal' cocktail of prescription drugs from his bottle and a syringeDespite being revived at the scene and brought to hospital, Oakley later succumbed to brain injuries caused by the overdose on December 31, 2024. Sentencing Barnett to life in prison with a minimum term of 22 years, Judge Sweeting 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 'set about planning (her) own death in advance,' and acknowledged she had a 'recognised mental health disorder.'Addressing Barnett, Judge Sweeting said that although the circumstances of the case were 'nuanced and complex', the 'aggravating features outweighed those in mitigation.'He said: 'Oakley was exceptionally vulnerable. He was only a baby of 14 months and wholly dependent on you to care for him.'During the sentencing hearing, Christopher Paxton KC, prosecuting, argued Barnett should face a whole life term given the premeditation of the killing.He said: 'It can properly be concluded that Ms Barnett was planning to kill Oakley and then herself.'He said she had known 'for weeks she knew the removal of Oakley was inevitable'. Barnett was arrested in the loft as officers desperately fought to save her son's life. He died weeks later in hospital Dramatic police bodycam footage showed officers asking Barnett if she and her baby were okay – before she suddenly confessed: 'I killed him.'Yet, he said, she 'rejected offers of help as she wanted to keep Oakley close to her so she could carry out her premeditated plan to kill Oakley then herself'.Mr Paxton said Barnett made 'substantial efforts to create a false trail to create the impression that she was not at home,' such as leaving her car in Epping Forest and then walking home.In reality, he argued, Barnett had locked herself in the loft of her home in the lead up to the killing while a court hearing over Oakley's care was ongoing.Barnett had joined the court remotely, after claiming that Oakley had fallen in with gastroenteritis and that no one else could take care of him.Mr Paxton told the court this was a ruse, with a number of care workers and her own mother contradicting her claims.He said: 'She rejected offers of help so she could keep Oakley close to her to carry out a predetermined plan to kill Oakley and then herself. 'It does not appear that anyone actually witnessed Oakley's symptoms as Ms. Barnett reported them.'Mr Paxton added Barnett collected prescription medications that 'she was not by her own admission taking' before mixing them in a 'child friendly way' in a baby bottle and syringe. He also said Barnett 'had hidden numerous items in the loft in advance of the hearing itself.' In mitigation, defence barrister Jonathan Higgs KC claimed that this was not true.He said: 'Undoubtedly, Oakley was seen face-to-face by a doctor, not over the phone, and diagnosed with gastroenteritis.'Mr Higgs argued that although the jury had found that she had shown intention, it was not necessarily the case that she had planned to kill Oakley.Addressing Justice Derek Sweeting, he added: 'the most obvious issue my lord will need to consider is not whether or not there was an intention to kill and that intention was formed when the drugs were put into a drinks bottle.'In an impact statement read to the court, Oakley's father Jake Rose said he was 'heartbroken and devastated.' He said: 'I'm not never going to see my little boy grow up.'My life and heart is now always going to be filled with a massive void of never getting to know my precious boy.'Barnett gave evidence during the two-week trial and continued to deny any plan to kill her son. She was found guilty following an earlier trial. Barnett showed no reaction as the sentence was handed down.