DNA sample from under Ashling Murphy’s nails matches suspect’s profile – court

A sample taken from underneath the fingernails of Ashling Murphy matches a DNA profile of the man accused of killing her, a court has been told.

Ms Murphy, 23, was killed while exercising on a canal path in Tullamore, Co Offaly, at about 3.30pm on January 12 last year.

Jozef Puska, 33, of Lynally Grove in Mucklagh, Tullamore, has pleaded not guilty to the schoolteacher’s murder.

Appearing before the Central Criminal Court, Dr Lorna Flanagan said she compared a profile of DNA taken from underneath Ms Murphy’s fingernails with a profile taken from a buccal swab of Puska and a sample of his blood.

Dr Flanagan, who has been working in the DNA section of the Forensic Science Laboratory for eight years, said she was carrying out a male-specific profiling method known as YSTR in this case.

She explained to the court that this was different than the autosomal profiling the jury had heard of on previous days as it exclusively looks at the male-specific Y chromosome.

She said this is inherited along the male paternal line, and that all males along that line share the same characteristic.

Dr Flanagan explained that YSTR can be “exploited” to ignore all female DNA in a sample and focus on the male DNA.

She said YSTR is like a “magnet” that pulls the “needle” of male DNA out of the “haystack” of female DNA in a sample.

Dr Flanagan said analysts would generally see someone’s own DNA underneath their fingernails and a fingernail sample is used to show that two people had interacted with each other in more than a passing or social contact.

The swabs came from both the left and right hands of Ms Murphy.

Dr Flanagan said the YSTR DNA profile, which looks at 23 different areas of the Y chromosome, from under Ms Murphy’s fingernails matched the YSTR DNA profiles of the blood sample and buccal swab from Puska.

The court heard that it is very likely that a father and son, brothers and fraternal male cousins have the same profile.

She said the likelihood of finding this profile from someone unrelated to Puska was one in 14,000.

She said the probability is reliant on a database of samples representative of the Western European population.

Dr Flanagan said the estimate would be “considered conservative”.

Detective Sergeant David Scahill explained to the court how he had analysed CCTV and phone records to determine that two of Puska’s brothers were not near the canal at which Ms Murphy died at 2pm or any time thereafter.

The court also heard from Detective Inspector Brian Farrell, who was a lead investigator into the killing of Ms Murphy.

Taking questions from defence barrister Michael Bowman SC, Mr Farrell told the court that he had regularly noted Puska as an SO, or suspected offender, in his notes.

He said that this continued after another man arrested in the case had been ruled out through DNA evidence.

Mr Farrell said that “person of interest” is not a term he would use.

Asked if he would have informed the gardai who were travelling up to Dublin to question Puska about his whereabouts after the other man had been released, Mr Farrell said he could not say that he did not but he would have “treated it very much as a need to know” and not something he would usually do.

He described it as a “fast-moving investigation”.

Mr Farrell told Mr Bowman that his notes included instructions to ask Puska about his whereabouts, injuries, and his bike.

The senior garda said he could not say if he told them to look at Puska but said they were experienced detectives and “you’d expect them to”.

Under questioning from Mr Bowman, Mr Farrell said he had written in his notes that he asked gardai speaking to Puska to “read back over as many details as possible” before inviting him to sign.

He said he told them not to question him after reading back the notes but said they could take down anything he says afterwards.

Mr Farrell also told the court he was in touch with nurses in the hospital about Puska’s likely release date.

He was working in concert with Detective Superintendent Patrick O’Callaghan who told the court that there were more than 720 lines of inquiry followed in the murder investigation.

Senior counsel for the prosecution, Anne-Marie Lawlor, asked Mr O’Callaghan if he was aware of how Ms Murphy had died at the time Puska told Detective Fergus Garda Hogan on January 14 that he had “cut her”.

The senior garda said he himself was aware but it was a decision of the investigation team not to release information on how Ms Murphy died and that Mr Hogan would not have been aware at the time.

He said the information would not have been in the public domain.

Mr Bowman asked if another man who had been earlier arrested as part of the investigation had been asked about knives and if this was something being pursued.

Mr O’Callaghan said: “I’ll accept that.”

Mr Bowman asked whether paramedics on the scene would have seen Ms Murphy’s wounds, to which Mr O’Callaghan said: “There were wounds visible.”

Mr Scahill later explained to the court that he was the garda that arrested Mr Puska following his hospital discharge at 11.31am on January 18.

He said Mr Puska was charged with the murder of Ms Murphy at Grand Canal Way, Cappincur, Tullamore at 19.42 on January 19.

Mr Scahill said he cautioned the defendant and Puska’s reply was: “No.”

The trial continues.