Puska, of Lynally Grove in Mucklagh, Tullamore, had pleaded not guilty to the 23-year-old’s murder, but a jury of nine men and three women reached their unanimous verdict after beginning deliberations on Wednesday.
Judge Mr Justice Hunt told the jury “we have evil in this room” after Puska was found guilty.
Justice Hunt said: “There will be a day of reckoning for Puska.”
At the time of her murder, Murphy had been out for a run on a sunny January afternoon. She had covered 3.2km when she was randomly attacked by Puska, a man she had no past connection with.
Her fitness tracking app was still running when she was found fatally injured in thick undergrowth adjacent to the canal path.
Her smartwatch recorded a sudden erratic movement at 3.21pm, the moment Puska struck.
The circumstances of her murder – the indiscriminate stabbing of a young woman who was simply out for some exercise – resonated across the globe.
The jury were applauded as they exited the chamber as Ms Murphy’s mother held up a framed photograph of her daughter.
Ashling’s father Ray along with Ashling’s mother Kathleen, her sister Amy, brother Cathal and long-time boyfriend Ryan attended the trial at the Central Criminal Court in Dublin.
During three weeks of evidence, the jury was shown maps of the Tullamore area; CCTV footage taken from Garda cameras, businesses and schools in the town; forensic evidence; data from Ms Murphy’s Fitbit smartwatch and evidence from witnesses who were along the canal.
Giving evidence from the witness box last week, Puska said he was “trying to help” Murphy after she had allegedly been attacked by another man, who he said had also attacked and stabbed him.
The court had also heard evidence from gardai who said Puska admitted killing Murphy while receiving treatment at St James’s Hospital in Dublin on 14 January.
Justice Hunt thanked the jury for their service and exempted them from further duty for 20 years, adding that the prompt verdict reflected that it was a straightforward case and he was satisfied the verdict was correct.
The judge said the case dealing with Murphy’s killing was particularly difficult given “the kind of person that she obviously was”.
He told the court that to lose a child was unnatural. Speaking of the Murphy family, he said: “Their position is unenviable. How their child was taken away, to consider what happened here is enough to make you physically ill.”
Women’s Aid has welcomed the conviction.
In a statement, the charity said: “When Puska senselessly took Ashling Murphy’s life at 4.30pm in broad daylight while she was out on a run, it sent a shockwave through communities in Ireland.
“That this could happen tapped into a visceral feeling that so many girls and women are socialised to feel – that the risk of male violence is everywhere. That nowhere is safe.
“The murder of Ashling Murphy was a shocking example of dangers posed to women and the case put a spotlight on the inherent risk of male violence in society. Every woman should have the right to be safe, both in their own homes and in their communities.”