The bright evening sunshine was in stark contrast to the sombre mood as mourners came to lay flowers and pay tribute.
Scottish and Irish songs were sung — among them Cork’s anthem The Banks of My Own Lovely Lee — at a vigil for Karen.
Flanked by members of the college’s GAA team, her classmates from Glasgow Caledonian University came together at the base of the Sir Walter Scott column in the square to place flowers, candles, cards and notes expressing their grief at her untimely death.
Marian Buckley hugged husband John as they read messages of sorrow and support for the family.
“No words can express our shock and sadness,” read a note placed at the foot of the Scott memorial as the students gathered in tearful remembrance.
Karen’s family, who travelled to Scotland on Tuesday, have said they are “absolutely heartbroken”. Her father John Buckley, 62, described Karen as an outgoing girl who “thoroughly enjoyed life”.
“Marian and I, together with our sons Brendan, Kieran, and Damian, are absolutely heartbroken,” said a statement released through police in Scotland.
“Karen was our only daughter, cherished by her family and loved by her friends. We will miss her terribly.”
Fiona Hyslop, Scotland’s Cabinet Secretary for Culture, Europe and External Affairs, said her government would give any support they could to the Buckley family.
“Scotland and Ireland have a strong and enduring friendship, and our two nations are united in grief and sorrow at the events that have unfolded this week,” she told the Irish Examiner.
Earlier, 21-year-old Alexander Pacteau was charged with Karen’s murder and also for attempting to defeat the ends of justice.