Police feared that Pacteau may have stalked women in different cities
Police in Scotland widened their search for women who may have been stalked by Karen Buckley's killer Alexander Pacteau beyond Glasgow to cities including Edinburgh and Dundee.
Glasgow detectives immediately feared for the safety of the Irish nurse (24) once they identified Pacteau (21) from CCTV security camera footage.
He was spotted as being the young man engaging her in conversation after she left The Sanctuary nightclub at 1am on April 12 this year.
One officer was aware of the fact the young man had been acquitted of a serious sexual assault in Glasgow just two years previous.
A trawl of more than 1,900 hours of CCTV footage from 49 different premises around Glasgow revealed to detectives that Pacteau may have attempted to stalk another woman in the city. One attempt was frustrated and the woman, identified and traced because of a distinctive dress she wore, was totally unaware of Pacteau following her.
Police in Scotland were so concerned about Pacteau after Karen's murder that they conducted a detailed examination of his personal life and movements since 2011.
The young man operated a failed courier business for a time - and travelled to Edinburgh as well as regional Scottish cities such as Dundee.
Police conducted an exhaustive analysis of all these areas to determine if any young women had reported incidents of being stalked or approached in suspicious circumstances.
Scottish detectives also conducted discreet inquiries amongst escorts in the Glasgow area to determine if any knew Pacteau or may have been followed by him.
Glasgow High Court heard that there was no evidence of a sexual assault in Karen's murder. Both the trial judge and senior detectives described the savage killing of the University of Limerick graduate as "motiveless".
Pacteau claimed in the previous 2013 sexual assault trial that he was gay.
However, it has now emerged that Pacteau, despite his claims to be gay, was infatuated with pretty young women.
He was also increasingly angry at being rebuffed by women who found him awkward and strange.
Neighbours near Pacteau's Dorchester Avenue flat nicknamed him 'Shrek' because of his hulking size and brooding manner.
The former grammar schoolboy must now serve 23 years in prison for murder before he can be considered for parole.