Nicholson will serve a minimum of 33 yearsCredit:Hampshire Constabulary/PA “She was also vulnerable and newly romantic and this made her an easy target for someone looking to satisfy his own appetites. The man who took her life was just such a person.”It seems Lucy developed a crush on Nicholson. Instead of rebuffing her, he encouraged her to continue her interest in him. She was available and he took full advantage.”Notes written tell the full story, at once they are heartfelt and stomach-turningly explicit. The mix of mature insight and young confusion serves as a powerful reminded to show why there’s a need for an age of consent. Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings. A 13-year-old schoolgirl’s “narcissistic” killer has been jailed for life, after a judge described the killing as “pitiless execution” he used to escape being exposed as a paedophile.Care worker Stephen Nicholson, 25, will serve a minimum of 33 years for raping and murdering Lucy McHugh.Nicholson killed Lucy McHugh in July last year after their “secret sexual relationship turned sour”, a court heard on Thursday.Nicholson, originally from Southampton, lured Lucy to her death in woodland at Southampton Sports Centre on July 25 last year.When she arrived, prosecutors said he “brutally” stabbed her, leaving almost 30 knife wounds which included three “very dangerous” cuts to the carotid artery in her neck. Lucy McHugh was killed in July last yearCredit:Hampshire Police/PA Sentencing Nicholson, the judge, Mrs Justice May, told him: “This was a pitiless attack on a child following months of sexual exploitation.”The prosecution has described it as an execution and I am satisfied this is correct.”The combination of his cold narcissism and hot anger dictated that she had to be put out of the way and he saw to it that this was done.”The judge added: “Lucy McHugh was brutally murdered. She was just 13 years old. Any sudden death is a tragedy, but the violent death of a child is shocking.”Lucy was described as bright, bubbly, intelligent and eager to learn. Her grandmother said her nickname was ‘Brains’ because of how quick she was. “Nicholson used and abused Lucy. She had ceased to be of interest to him and had become an obstacle to his comfortable life.”There was also the real risk of her making good on her threat to out him as a paedophile. As far as he was concerned, she had to go.” Lucy McHugh was last seen heading towards the sports centre where Nicholson killed herCredit:Hampshire Constabulary/PA “He has targeted Lucy, taken advantage of her and when she wanted a relationship with him, he has taken the decision to silence her once and for all by brutally killing her,” he said. The investigation into Lucy’s death, described by the CPS as “one of the largest in criminal history” was hampered when Nicholson refused to give police his Facebook password.After applying through the US courts for access to his account, prosecutors only received a log of his Facebook contacts with Lucy but not the content of any messages. It finally arrived the day that the trial started.Detective Superintendent Paul Barton, of Hampshire Police, said Nicholson was a “cold and calculated predatory paedophile” who preyed on vulnerable girls to satisfy his sexual appetite.