Eerie images released by police detail circumstances surrounding Karen's murder
Alexander Pacteau has pleaded guilty to the murder of Irish student Karen Student in April of this year.
The 21-year-old, who repeatedly hit his victim on the head and body with a spanner, pleaded guilty when he appeared at the High Court in Glasgow.
A major search was launched for 24-year-old Miss Buckley, from Cork, when she was reported missing from the flat she shared with friends after failing to return home from a nightclub in Glasgow's west end in April this year.
Her body was found days later at a farm on the outskirts of the city.
Following his guilty plea, police have made the decision to release images and footage which document the horrific murder.
One of the images released shows Pacteau's Ford Focus car parked at Kelvin Street. It was there he said he carried out the murder.
He told police he first attempted to strangle the University of Limerick (UL) nursing graduate in his car before beating her to death with a heavy spanner.
Another eerie image shows the inside of Pacteau's flat where he kept Karen's body for days wrapped in a sheet.
Police were able to analyse soil found on the 21-year-old's tyres with that of High Craigton Farm, where Karen's body was discovered.
Lord Advocate Frank Mulholland QC, prosecuting, told the court how Pacteau drove to his flat and took Miss Buckley's body inside to his room after she had been reported missing.
At 8am he used his mobile phone to look up the properties of a chemical called sodium hydroxide, or caustic soda. He then locked his bedroom door and travelled to a B&Q store where he bought six litres of the chemical and masks and gloves, the court heard. He also went to a Poundstretcher store near his flat and bought more of the chemical.
He texted his flatmate to make sure he was out for the day, then returned to the flat and left Miss Buckley's body in the bath.
Pacteau was found cleaning the hall and stairwell when his flatmate returned home at around 8pm. He had moved her body into his locked bedroom again wrapped in a duvet, the court heard.
While waiting for the Ford Focus to be cleaned, Pacteau used his phone to create an advert to sell his car.
Police officers knocked on his door around two hours later after he was identified as the man talking to Miss Buckley on CCTV.
As he opened the door to the police Pacteau said "I was just coming to see you", Mr Mulholland told the court.
The officers noticed a strong smell of bleach in the flat and a tool box and other items in a bedroom.
Pacteau agreed to go with the officers to the station as a witness. During a search, police found a Poundstrecher receipt for a series of chemicals and padlock keys in the 21-year-old's pockets.
He gave a statement saying he met Ms Buckley outside the club and they both went back to his flat where they had consensual sex.
He told police Miss Buckley had fallen and injured herself on the bed frame but he did not notice she had been bleeding until the following morning, and when he realised police were looking for information regarding her disappearance he panicked.
He told them he had burned the mattress and clothes on a forest road near Drymen and he did this because he was aware he was the last person to see her alive.
Meanwhile, police searching his flat removed items to be examined and Miss Buckley's blood was confirmed as being within the property.
When he was detained by police, officers recovered a hand-written note containing the account of what he had earlier told police.
The Lord Advocate said it was now accepted by the accused that his statements were untrue.
The court heard how a member of the public had contacted police after reading that Pacteau was the last person so see Karen and realising police were looking for information on a vehicle seen on roads near Drymen, the witness told officers about the storage unit at the farm that Pacteau used in the past.
Police then went to High Craigton Farm where they found the blue plastic barrel containing Miss Buckley's body.