A 'vile' former police officer who once plotted to become a serial killer has been locked up again after sharing sick online fantasies about women and girls.Brian Darby, 80, had begun searching for child abuse images within days of being released from prison in 2017, after serving 15 years of a life sentence for his depraved past.Darby was jailed in 2002 after putting his murderous plans into action, stalking potential victims and breaking into one woman's home before slipping a wire around her neck.He had admitted at the time he wanted to be 'as evil as possible'.Wood Green Crown Court in London today heard he started looking at indecent pictures of children online almost as soon as he was freed on licence, which ordinarily compels criminals to adhere to strict rules regarding their release from prison.When he was arrested in February this year, after creating and distributing indecent images of children that he had created using AI, police also found a series of online chats where he had shared horrifying rape and murder fantasies.He pleaded guilty to nine obscene communications charges, three counts of making indecent photographs of a child, and two counts of distributing indecent photographs of a child.Judge John Law sentenced Darby to four years in prison, with an extra two years on licence once released - but warned he may never be released. Back behind bars: former Leicestershire police officer Brian Darby, 80, has been handed a new four-year prison term after previously serving a life sentence for over his murderour fantasies Prosecutor Bartholomew O'Toole told the hearing Darby had posted a sexual fantasy involving killing children on Reddit, and online chats featured his ambitions to strangle, smother and drown women.He said one post spelled out the 'strangulation of his wife with family gathering around to voice encouragement and advice'.In another post, Darby said schools should 'train girls to be sex slaves and dominatrices', while women should be killed at the age of 30.The judge said Darby was 'emotionally detached and indifferent' when quizzed about his latest set of offending, and 'did not appear to be embarrassed or ashamed'.He said the online rape and murder fantasies 'echo' Darby's 2002 convictions for attempted murder, conspiracy to murder, and aggravated burglary.Assessing Darby as a dangerous offender, the judge pointed to his 'entrenched interest in violent sexual material involving children and adults, your online dissemination of that material and fantasies, and a pattern of offending'.Darby was sacked as a PC at Leicestershire Police in the 1970s when he was convicted of indecently assaulting boys.He went on to work as a health and safety officer for the BBC in the 1980s, the court heard.Detective Inspector Andy Cook of the Met's Online Child Sexual Abuse Exploitation team, said: 'The Met takes offending of this nature incredibly seriously and we are committed to bringing those who share indecent images of children to justice.'Darby is a vile individual whose previous offending makes this case all the more disturbing.'We launched an investigation as soon as we received intelligence that he was suspected of uploading indecent images of children to the internet. Darby was arrested in February and was immediately recalled to prison.'Extensive digital forensic work on Darby's phone by Met detectives helped build a strong case against him. He was left with little option except to face up to what he had done.'In 2001, Darby admitted attempted murder and was convicted at trial of conspiracy to murder alongside his lover Jeanette White.The Old Bailey heard White was 'under the spell' of Darby as they exchanged around 450 pages of letters about serial killing, rape, cannibalism, and necrophilia.By 2000, the fantasies had been turned into reality as the couple plotted to murder a woman and her children in their home in Westminster, while Darby answered adverts from women looking for a room to let so that he could stalk them.A 45-year-old mother narrowly escaped death when Darby called at her home in Ealing, west London, posing as a BBC researcher.He placed a wire noose around her neck intending to rape and kill her, but she managed to escape into the street, the 2002 sentencing hearing was told.The court heard today that Darby used encryption technology to try to hide his identity when he used AI online to create the indecent images of children.Olivia Beach, representing Darby, said he accepted his actions were 'wrong', and he blamed it on 'addiction which is something out of his control and there is nothing he can do about it'.The court also heard Darby volunteered in prison to listen to the problems and issues of other inmates.Darby, from Enfield, north London, will serve around two and a half years of his prison term before being considered for release, but he must now also convince the Parole Board that he is safe to be freed again from his life sentence.