SHOWING six university housemates embarking on one of life’s great adventures, it is an all-American image of youthful joy.
Wearing blue jeans, a crop top and a vivacious smile, carries giggling best friend on her shoulders.
On the right is college junior Xana Kernodle, with her basketball-playing boyfriend Ethan Chapin’s arm draped lovingly round her.
But just hours after Kaylee posted the image on Instagram — with the words, “One lucky girl to be surrounded by these people everyday” — the four were brutally murdered in their beds.
And as suspect Bryan Kohberger — a PhD student in criminology — appeared in court this week, one key question is being asked.
Were these brutal, senseless deaths nothing more than an attempt to pull off the perfect crime?
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On November 13 last year, the killer had crept into the student house in the usually sleepy college town of Moscow, Idaho, and frenziedly stabbed the friends with what detectives say was a large knife.
Such was the savagery of the killings that blood was later seen seeping through the outside wall.
The other two young women in the photo — on the left and on the far right — reportedly slept through the carnage in the same property.
America, which is no stranger to horrific deaths, was left both appalled and uneasily fascinated by a killing that apparently had no suspect and appeared motiveless.
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Days became weeks, and as cops and the FBI sifted through DNA evidence and an avalanche of tip-offs, there was no clear breakthrough.
Meanwhile, nine miles across the state line in Pullman, Washington, the man now charged with the murders was quietly carrying on with his postgraduate studies in criminology.
Frozen with shock
If suspect Kohberger, 28, who “believes he will be exonerated”, is found guilty of the murders, it will be hailed as a masterful piece of detective work.
As he had a clean record, cops are reported to have tracked him down by running the DNA from the crime scene through a genealogy website and matching it to a family member.
They then stole rubbish left outside the family home to get a match with Kohberger.
The day of the killings had started innocuously enough, with a university football game creating its usual buzz in the town.
Later the four victims, all students at the University of Idaho, would party in the town before making their way back to the clapboard house they shared close to the college campus.
Childhood friends Kaylee and Maddie, both 21, spent their evening about a mile and a half away at the Corner Club, a student bar in the centre of town.
They returned home at around 1.45am and shared a bed on the third floor as Kaylee made calls to an ex-boyfriend.
Housemate Xana was also out that evening.
She and her boyfriend Ethan, both 20, had been at a party at a fraternity house.
They too returned in the early hours of the morning, going to bed in Xana’s second-floor room.
Ethan, not a resident of the house, stayed over.
On the ground floor were survivors Bethany and Dylan, both 19.
Investigators later said that far from sleeping through the slaughter, Dylan actually saw the murderer.
At around 4am she was woken by a noise upstairs. She heard one of her housemates say: “There’s someone here.”
She stuck her head out of her bedroom but saw nothing. A short while later she heard what sounded like crying and a man say: “It’s OK, I’m going to help you.”
Dylan looked out of her bedroom again and saw a man in black with what looked like a ski mask over his nose and mouth.
Frozen with shock as the killer walked past her and out of the back door, she then locked herself in the bedroom.
It would be nearly eight hours before one of the surviving house mates called emergency services to aid “an unconscious person”.
No murder weapon was found and there were no signs any of the victims had been sexually assaulted.
A coroner later said some of the dead had defensive wounds, indicating that they tried to fight back.
Kaylee’s dad Steve said of his daughter and pal Maddie: “They’ve been friends since sixth grade.
“Every day they did homework together, they came to our house together, they shared everything. And in the end, they died together, in the same room, in the same bed.”
, a college community of 25,000 close to Idaho’s border with Washington state, was left eerily quiet.
A rural and friendly town, there had not been a murder there for seven years.
Many of the University of Idaho’s 11,000 students left town immediately after the murders.
At 4am, Dylan was woken by a noise. She heard a housemate say, ‘There’s someone here’, then crying, then a man say: ‘It’s OK, I’m going to help you.’
Other residents asked for guns or pepper spray for Christmas.
Locksmiths did a roaring trade, businesses closed early and few dared to walk the streets alone after dark.
Moscow’s 31-officer police department soon received assistance from FBI investigators and state troopers.
Cops were flooded with tip-offs from the public, many of which proved bogus.
As the investigation appeared — in public at least — to be making little headway, amateur internet sleuths filled the void.
While cops and the FBI painstakingly sifted through tip-offs and evidence at the crime scene, some relatives became frustrated at the apparent lack of progress.
On November 28 Kaylee’s father Steve said he was feeling “a little defeated” by the lack of arrests.
He said of the law enforcement officers: “I have to assume and hope that this is all part of their plan and they’ve got this figured out.”
Then, on December 7, came a breakthrough.
Police said they wanted to speak with the driver of a white 2011-2013 Hyundai Elantra which had been seen “in the immediate area” of the house around the time of the murder.
However, as the days passed, the investigation still seemed to be going nowhere.
As his semester ended in December, Washington State University student Bryan Kohberger prepared to drive home for Christmas.
With more than 2,500 miles to cover to reach Pennsylvania, his father Michael had flown out to join him for the journey.
After loading up a white Hyundai Elantra, they set off on the long trek.
On December 15, driving east of Indianapolis with Kohberger Jnr at the wheel, they were stopped twice by traffic cops, once for speeding and a second time, nine minutes later, for tailgating.
Kohberger was released with a warning on both occasions.
The officers involved said that at the time they had no information that was a suspect in the Moscow murders.
Unconfirmed reports in the US say that the authorities were tracking the pair on their journey and that the FBI had ordered cops to pull them over to obtain video of the suspect.
They were said to be desperate to know if he had any scratches or injuries on his hands.
The Kohbergers continued their trans-American journey to the family home in Pennsylvania’s Pocono Mountains.
Then on December 27 investigators took rubbish from outside their home in Albrightsville and were able to make a match with and DNA found at the crime scene.
On December 30 law enforcement officers finally believed they had enough evidence to pounce.
Following Kohberger’s arrest on four counts of first degree murder and burglary, his attorney Jason LaBar said his defendant “is eager to be exonerated of these charges and looks forward to resolving these matters as promptly as possible”.
When Kohberger shuffled into court in Monroe County, Pennsylvania, he was supported by his father, mother and sister, who believe he is innocent.
Cuts on his face
Kohberger agreed to be extradited to Idaho — and in shackles and red jumpsuit, he reversed his journey across America, this time on a police private jet.
Last week police released a trove of evidence they say implicates the student in the quadruple murder.
They claim Kohberger’s DNA was found on a Marines Corps knife sheath discovered on the bed next to Madison’s body.
Scouring video footage from the area, detectives spotted a white Hyundai Elantra driving past the house three times before stopping there shortly after 4am.
It left 16 minutes later “at a high rate of speed”. The cameras did not pick up the car’s number plate.
Cell phone data is said to reveal that Kohberger had stalked the student house on 12 occasions before the murders.
At the time of the murder, the FBI say Kohberger’s phone was switched off.
They say it pinged to life again at 4.48am on a road out of Moscow.
And in a chilling detail, investigators say their suspect had apparently returned to the vicinity of the murder house around five hours after the killings.
He was said to have returned there even before the police were called.
If Kohberger is guilty, then for a criminology student, he appears to have had a gung-ho approach to modern detective methods.
The dead-eyed student appeared in a Moscow court on Thursday with mysterious cuts on his face.
He waved his right to a speedy trial and will appear in court again on June 26.
Kaylee’s dad Steve has called for the death penalty, which in Idaho is administered by lethal injection.
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The grieving father added that the man accused of killing his daughter was a “broken soul” and a “pitiful human being” who had “finally got caught running”.
- Additional reporting: Thea Jacobs