Karen Buckley's killer Alexander Pacteau had been stalking other women in Glasgow
The killer of an Irish woman in Glasgow was investigated by Scottish police amid fears he may have stalked other women in the city.
Alexander Pacteau is now in protective custody in one of Scotland's toughest prisons, HM Barlinnie Prison, after the shocking revelations of how he bludgeoned Cork student Karen Buckley to death and then attempted to dissolve her body in a barrel of caustic soda.
It has been learned that police suspected another woman was being stalked by Pacteau, although she had absolutely no knowledge of being either followed or watched.
As a line of inquiry, it was subsequently dropped amid a lack of evidence.
But the woman was interviewed by detectives after they suspected Pacteau may have watched her following anecdotal indications from neighbours, acquaintances and colleagues of the young man.
CCTV security camera footage was also studied by detectives.
The woman, who was traced via a distinctive brightly coloured dress she wore, said she had no knowledge of being watched or followed.
The revelation came as Police Scotland admitted they now believe Pacteau was stalking a random female victim on the Dumbarton Road on April 12 - it was Karen Buckley's ill-fortune to cross on to the same side of the street as the hulking 21-year-old as she walked home alone.
Pacteau, also known as Alexander Barr, faces a life sentence after he pleaded guilty to the murder of the post-graduate student nurse at Kelvin Way in Glasgow just minutes after she left The Sanctuary nightclub alone on April 12 last.
The young man lured Karen into his Ford Focus car with the offer of a lift home, before first trying to strangle her and then beating her to death with a heavy spanner.
For a time he drove around Glasgow with Karen's body in the passenger seat of his car before trying to dissolve her remains in caustic soda in the bathtub of his flat and later in a plastic barrel. He then hid the barrel in a storage shed on an isolated Glasgow hill farm.
He will be sentenced on September 8.
Pacteau was acquitted in 2013 of sexually assaulting a 24-year-old Scottish woman. The alleged incident occurred in 2011 when Pacteau was just 17.
He vehemently denied the charge and told his trial he would "rather be charged with murder than attempted rape."
Pacteau was subsequently found not guilty by a majority High Court jury verdict after a four-day trial.
Det Supt Jim Kerr, who led the hunt for the Irish nurse, said police do not believe Pacteau's account of what sparked the fatal attack on Karen Buckley.
"We would describe him as being callous and calculating. That could have happened to any female that night," he said.