A school teacher has been jailed for life without parole for sexually abusing and murdering a 13-month-old boy he adopted with his partner, ending a case described by detectives as one of the most disturbing they have seen.Jamie Varley, 37, received a life sentence at Preston Crown Court on Thursday for the murder of Preston Davie, meaning he will never be released from prison. Her partner, John McGowan-Fazakerley, 32, was jailed for 25 years after pleading guilty to sexual assault, child cruelty and allowing the death of a child, The Guardian reports.The court heard that Preston spent the first months of his life in foster care before being adopted by the couple in April 2023. Less than four months after moving to his home near Blackpool, the child died.Prosecutors said Preston was routinely subjected to physical and sexual abuse while the couple lived together. Evidence presented during the trial revealed that he suffered 40 different injuries while in her care.When Preston was taken to the hospital on July 27, 2023, Worley claimed that the child had accidentally drowned after being left unattended in the bath. However, medical evidence immediately cast doubt on that account.Jurors heard that Preston’s hair was dry, he was still wearing a nappy and there was no evidence that he had swallowed water. A subsequent Home Office post-mortem investigation ruled out drowning and concluded that he died due to obstruction of his airway by an object or objects.The trial also heard that Preston had previously been taken to hospital several times due to concussions and other injuries, raising concerns among medical professionals.After an eight-week trial, jurors found Worley guilty of murder and several other offences, including sexual assault of a child, grievous bodily harm, child cruelty and indecent image offences.McGowan-Fazkerley was convicted of allowing the death of a child, child cruelty and sexual assault.Detective Chief Inspector Andy Fallows said the abuse began soon after Preston was placed with the couple.Describing the pair as “pure evil”, she said: “For the first nine months of his life Preston was a happy and healthy baby but by the end he was a broken shell.”The judge said that the seriousness of Varley’s crimes justified one of the most severe sentences available under English law, ensuring that he would spend the rest of his life behind bars.