The man who killed teenager Georgia Williams plotted the murder to give himself "sadistic pleasure", the judge said.
Mr Justice Wilkie said in sentencing: "You watched her die in circumstances where you could have saved her - and doing so was a central part of your pleasure...[You] then treated her body with contempt, dumping her in a remote area."
Continuing to address Jamie Reynolds, who stood head bowed and with his hands clasped behind his back, he said: "This is not a marginal or borderline case. I am in no doubt the seriousness of your offending, so a whole-of-life term is the starting point."
"I take very seriously the conclusion of (psychiatrist) Prof Paul Peckitt that you have the potential to become a serial killer," he added.
A 23-year-old man killed teenager Georgia Williams after luring her to his parents' house and hanging her, a court has heard.
Jamie Reynolds was a "a sexual deviant", "a manipulative and conning individual who operated in denial" and had "a morbid fascination" in extreme pornography depicting violence against women, prosecutor David Crigman QC said.
Reynolds pleaded guilty earlier this month to murdering 17-year-old Georgia in May, on what was scheduled to be the first day of his trial at Stafford Crown Court.
Mr Crigman said that at the time of his arrest for murder, Reynolds had 16,800 images and 72 videos of extreme pornography on his computer, including digitally-doctored images of up to eight other women he personally knew in which ropes had been added around their necks.
A senior officer investigating the murder of schoolgirl Georgia Williams paid tribute to the incredible dignity of her family, and said the he was glad they were spared the further trauma of a full trial.
Speaking outside Stafford Crown Court after Mr Reynolds changed his plea to guilty, Superintendent McGee, a senior investigating officer on the case said:
“It is important that Mr Reynolds pleaded guilty today as this at least saves Georgia’s family the further trauma of a full trial. We know the plea does nothing to ease their pain but hopefully it will help them begin to move forward with their lives once sentence is passed.
“The Williams family have been incredibly dignified and understanding throughout our investigation and I cannot praise them highly enough.
“This was a hugely challenging and unusual case for the police officers and staff involved and I’d like to thank everyone who has played a part in helping the investigation reach this point."