BY ALISON O’RIORDAN
A PARTIAL DNA profile generated from material preserved 42 years ago matched that found on a beanie hat taken from a murder accused, a court has heard.
UK forensic scientist Dr Jonathan Paul Whitaker testified that the probability of the recovered DNA profile originating from someone unrelated ‘to the man in the beanie hat’ would be one in 23,000.
Noel Long (74) of Maulbawn, Passage West, has pleaded not guilty to murdering 54-year-old Nora Sheehan between June 6th and June 12th 1981 at an unknown place. Her body was found by forestry workers at Shippool Woods near Innishannon six days after she went missing.
Evidence has been given that a microscopic slide containing material from a vaginal swab of the victim had to be sent to the UK in 2008 to generate a DNA profile, as Ireland lacked the technique at the time.
The jury has heard that the pathologist who carried out the post mortem on Nora Sheehan found internal bruising and the presence of spermatozoa. Dr Robert Dermot Coakley conducted the post mortem on Mrs Sheehan on June 13th, 1981 but died a few weeks later.
Dr Whitaker from Forensic Science Services (FSS) in the UK told Brendan Grehan SC, prosecuting, in the Central Criminal Court that Low Copy Number (LCN) was a more sensitive DNA profiling technique capable of detecting DNA in much smaller amounts. In November 2008, Dr Whitaker received a microscope slide of cellular material taken from the body of Mrs Sheehan and a blood stain card from the victim.
Dr Whitaker tested the microscope slide using the LCN methodology to maximise the chance of getting a DNA profile from the sample, as it was quite old and taken from the decomposed body. The blood stain card of Mrs Sheehan was processed by the standard DNA method.
Dr Whitaker said a DNA profile from the beanie hat provided to him in May 2022 was compared to the profile obtained from the seminal part of the microscope vaginal slide. Dr Whitaker said the profile taken from the semen on the microscope slide matched the DNA recovered from the beanie hat.
The witness said that if the male DNA profile on the microscope slide had not come from the person whose DNA profile was on the beanie hat, then it must have come from somebody else who by chance had the same DNA profile. Regarding the probability of that particular DNA profile originating from someone unrelated ‘to the man in the beanie hat’, he said it would be one in 23,000.
The next witness, forensic scientist Dr Dorothy Ramsbottom, said she was asked to offer her view of a match between material on Mrs Sheehan’s swab and the black beanie hat, based on the Irish population. She estimated it was at least 20,000 times more likely that the DNA matched that on the beanie hat, rather than an unrelated person, based on the database of the Irish population.
Under cross-examination, Michael Delaney SC, defending, asked the witness what the likelihood ratio would be if a full profile obtained from the semen on the swab had matched the profile obtained from the beanie hat. Dr Ramsbottom said it would be a thousand million times more likely where there was a match between two full profiles.
Detective Garda David Barrett, of Bandon Garda Station, agreed that this case had been with the serious crime review team from 2008 to 2016 before it was returned to Bandon Garda Station.
Det Gda Barrett said he had undertaken an extensive search in Bandon district headquarters, which comprised seven garda stations, for exhibits in the case. He agreed that 281 items were recorded on the exhibit log from the investigation but no items were recovered as part of his search. These items included a blue and white flowered dress found on Mrs Sheehan’s body as well as a blue coat, a shoe with a gold buckle and tights found at the scene. Det Gda Barrett said the accused had been charged with the offence on June 28th, 2022.
The prosecution has completed its evidence. The trial continues.
