A knife-wielding sex attacker who roamed a beauty spot for potential victims has been jailed for the "savage and brutal" murder of an 18-year-old student.
Ellen Higginbottom was killed by Mark Buckley when she took a break from studying for her A-levels and went out for a walk.
Buckley had earlier approached other lone women in Orrell Water Park in Wigan and engaged them in conversation before walking away.
But Manchester Crown Court heard how the 52-year-old overpowered Ms Higginbottom and cut her throat, before stealing her laptop, mobile phone and other personal possessions.
Sentencing Buckley to serve a minimum of 31 years in prison, Judge David Stockdale QC said the facts of the case were "frankly chilling".
Buckley pleaded guilty to murder last week.
The court heard that while Ms Higginbottom was not able to fight off her attacker, "her wounds indicated that she tried albeit in vain to defend herself".
Ms Higginbottom was only 5ft 4in and weighed just 5st 5lb, meaning she "did not stand a chance", the judge said.
The court was also told that while the Winstanley College student's murder appeared to be random, the attack itself was pre-meditated and involved "considerable planning".
Between 5.30am and 2pm Buckley approached three female dog walkers in the park and spoke with them briefly before walking off.
One of the women recalled he was clutching a green plastic carrier bag that was later discovered at his mother's home in Orrell.
Inside the Home Bargains bag were Ms Higginbottom's possessions, a length of rope, other pieces of ligature, an empty condom packet and sachets of sexual lubricant.
Buckley was also carrying a knife.
"The purpose was to subdue, sexually assault and murder a female," Peter Wright QC, prosecuting, told the court.
At about 2.15pm a female passer-by heard what she thought was a couple engaging in sex in some bushes off a pathway in the park.
Mr Wright said "in all likelihood" what the woman had heard was in fact the fatal attack on Miss Higginbottom.
The Honorary Recorder of Manchester told the defendant: "You subjected her [Ellen Higginbottom] to a savage and brutal attack. You inflicted many wounds in cutting her throat and killing her.
"It was as cowardly and callous as it was brutal.
"She would have had no idea it was coming. She would have been caught entirely off her guard.
"You were armed with a knife. She simply did not stand a chance.
"What must have been going through her mind is beyond imagining."
Judge Stockdale added that one of the aggravating factors of the offence was that it was "plain" that the attack took "some little time" and that Ms Higginbottom's death was "not instantaneous".
Following the aspiring vet's murder, Buckley returned to the park and moved her body which he intended to bury under cover of darkness on in a nearby wheat field.
However, he abandoned his plan after being picked up by a police helicopter with heat-seeking equipment, when he returned in the early hours of June 17, the day after the murder.
Ms Higginbottom's partially dressed body was discovered next to a hedge with a spade close by, and it appeared a belt had been used to drag her by the ankles.
The prosecutor said that the teenager could have been subjected to a sexual assault, but there was no forensic or scientific evidence to confirm this.
Buckley was arrested at his home in Preston two days after the murder and admitted killing Ms Higginbottom but could offer no explanation for his actions.
- When police arrested Buckley on suspicion of murder, he simply asked them to "lock up" his house once they were done there.
Ms Higginbottom's parents, Michael and Kay, did not attend the sentencing as Mrs Higginbottom is "gravely ill".
In a statement, Mr Higginbottom said: "We were tremendously lucky to have shared 18 years with her [Ellen Higginbottom] and everyone else who knew her will identify with that feeling.
"She made the world a better place with pretty much everything she said and everything she did.
"We all would have liked more though, and we would especially have liked for her to have had more.
"For her to have seen the results of all her hard work, for her to have seen her friends fly the nest as they went all to uni, for her to have explored the world that she was just growing into."
After Buckley was sentenced, Detective Superintendent Howard Millington of Greater Manchester Police, said: "I am glad Buckley will now be spending many years behind bars to contemplate the young life that he has stolen away, but I wish that we hadn't even had to investigate this crime.
"I wish it hadn't happened and Ellen was here celebrating her A Level results with her friends and planning her future."
David Graham, senior crown prosecutor in the North West, said: "Mark Buckley went out that day equipped with a knife to carry out a violent assault...
"We believe he selected his victim at random and Ellen Higginbottom was simply walking through the park at the time he chose to attack with tragic consequences."