A sexual deviant who killed a teenage girl by hanging her at his parents' house has been ordered to spend the rest of his life in jail.
Jamie Reynolds, 23, had a "morbid fascination" with depictions of extreme violence and was a potential serial killer, the court was warned.
Reynolds earlier admitted murdering 17-year-old Georgia Williams in Wellington, Shropshire, in May.
The judge at Stafford Crown Court said he deserved the severest sentence.
Mr Justice Wilkie said Reynolds had "enjoyed the spectacle of Georgia's ghastly few minutes" after meticulously planning the crime.
He accepted a psychiatric assessment of Reynolds that found he "had the potential to progressing to become a serial killer".
Prosecutor David Crigman QC said at the time of his arrest, Reynolds had 16,800 images and 72 videos of extreme pornography on his computer.
These included images of women he knew in which ropes had been digitally added around their necks.
He had written graphic short stories, which featured a fatal assault on a woman "followed by acts of sexual violation".
Mr Crigman described Georgia's murder as "scripted, sadistic and sexually-motivated".
'Damned by evil'
He said Reynolds took photographs of Georgia's body in different parts of the house, including on his parents' bed.
Although Georgia knew Reynolds "she made it clear she had no romantic interest in him".
She only agreed to go to the house to be a model for his amateur photography, Mr Crigman told the court.
Georgia's father Steve - a detective with West Mercia Police - read a statement to the hearing before sentence was passed.
He said: "We've been damned by evil to endure this sorrow and misery to the end of our natural lives."
Speaking outside court, he said that although Reynolds was serving a life sentence, the fact that "he still has life to hang on to" caused grief for the family.
Reynolds's barrister described the murder as a "horrific crime". He said Reynolds's actions were "unnecessary, tragic and selfish".
The court heard he was given a police caution in 2008, aged 17, for trying to strangle another teenager.
Georgia's family, from Wellington, last saw their daughter on 26 May and reported her missing two days later, after discovering she was not staying with friends as they thought.
In court they heard Reynolds had used Georgia's phone to answer her mother's concerned texts and to cover his tracks.
CCTV images showed he went to a cinema in Wrexham on the way to dispose of the teenager's body and showed "no external sign at all" of being "troubled", said the prosecution.
Reynolds was arrested in Glasgow the day after Georgia was reported missing.
After tracking the journey Reynolds's van took on the way from Wellington to Glasgow, police found Georgia's body in woodland off the Nant-y-Garth Pass in north Wales.
West Mercia Police said an independent review was being held into the force's contact with Reynolds before the murder.