A blood-stained blind cord that was wrapped around the neck of mother-of-two Lisa Thompson contained a mixed DNA profile for which murder accused Brian McHugh could not be excluded as a minor contributor, a forensic scientist has told his trial.
DNA recovered from jewellery found in the accused man's home also matched that of Ms Thompson, the jury also heard on Friday.
The jury has heard that Ms Thompson was dealing prescription drugs from her home and that she and Mr McHugh (40) had a "bit of a fling" in the year before she died. Evidence has been given to the Central Criminal Court trial that gardaí searching Ms Thompson's home found thousands of prescription tablets worth nearly €50,000 hidden in her attic.
Mr McHugh with an address at Cairn Court, Poppintree, Ballymun in Dublin 11, has pleaded not guilty to murdering Ms Thompson (52) at Sandyhill Gardens, Ballymun in Dublin 11 on May 9th, 2022.
The jury has heard that Ms Thompson was found inside the door of her home with multiple stab wounds to her chest and a window blind cord wrapped around her neck.
A pathologist has also given evidence that Ms Thompson's death occurred because of a combination of ligature strangulation causing asphyxia and multiple stab wounds to the left side of the chest.
Sarah Fleming from Forensic Science Ireland told David Perry BL, prosecuting, on Friday that she examined several exhibits seized during the investigation and compared them with DNA samples submitted from the accused, a named woman and Ms Thompson.
Ms Fleming said the cord, which was taken from around Ms Thompson's neck, was a light brown thin material measuring 128cm long and had a plastic clip near its middle.
The witness said as there was heavy blood-staining on areas of the cord she had targeted three areas which were not blood-stained.
The scientist said she found a mixed DNA profile with a major female contributor and a minor male contributor on one area of the cord.
She said all the DNA elements present in Ms Thompson's profile were present in the mixed DNA profile and the deceased could not be excluded as being a major contributor. She also found that all the DNA elements present in the accused's profile were present in the mixed DNA profile and he could not be excluded as being a minor contributor.
The witness said it was in excess of one thousand million times more likely that the mixed DNA profile originated from Ms Thompson and Mr McHugh rather than from Ms Thompson and an unknown person unrelated to the deceased and the accused.
The expert witness said she received swabs taken from the deceased's nails, the left side of her neck and her right side, the DNA of which matched Ms Thompson. The additional DNA elements present were unsuitable for interpretation.
Ms Fleming said she was provided with four rings seized from the accused's home at Cairn Court in Ballymun and took a combined DNA sample of the jewellery.
A detective had given evidence that a search was conducted at Mr McHugh's address on May 13th, 2022, three days after the deceased's body was found. Among the items seized was jewellery located in a drawer of a bedside locker in the accused's bedroom.
Ms Fleming said she found Ms Thompson and the accused as being the two main contributors on the rings. She said the mixed DNA profile was in excess of one million times more likely if it came from the deceased, the accused and an unknown person rather than if it came from three unknown people.
Under cross-examination, the witness agreed with Karl Monahan BL, defending, that there had been three contributors to the combined DNA sample on the four rings.
Ms Fleming said that as the rings had been packaged together she could not say which one the DNA profile was attributed to.
"I thought combining the DNA from the four rings onto one sample would increase my chances of getting a usable DNA profile," she added.
The witness further agreed that swabs taken from under Ms Thompson's nails did not reveal any DNA from the accused.
The trial continues on Monday before Ms Justice Karen O'Connor and a jury of four men and eight women.
