JurisdictionAL Experience
Roebuck forensics proffers authoritative expert witness testimony in all jurisdictions throughout Australia and select international courts. Oral testimony can be delivered in person or via audio visual link, depending on Counsel and jurisdictional requirements.
Since 2002, Helen Roebuck has handled 1000’s of indictable criminal matters before the courts, including offences of murder, sexual assault, firearms and major drugs trafficking.
A brief selection of matters in which Helen has taken instructions are listed here.
Further details can be made available upon request of Counsel.
IED – Attempted murder – DNA transfer – STRmix – Not guilty
In 2019 an improvised explosive device was located underneath a Belfast Police Officers vehicle, which was parked in his home driveway. The prosecution was substantially reliant upon DNA expert evidence to prove the charges.
The IED broadly comprised of a timber box, mercury tilt switch, a 9 volt battery and TNT.
“ I was called upon by the defence team in Ireland to provide DNA expert opinion relating to the STRmix output files associated with the DNA profiles obtained from the wires, connectors and terminals”.
“ Due to the very low amounts of DNA attributable to Granaghan it cannot be determined whether the DNA was deposited by direct contact with the items, or through indirect transfer”
Judge Fowler (2022);
[98] A significant circumstance in this matter is that the prosecution’s case relies on the defendant’s DNA having been deposited in the device at the time of construction. Considerable credence must be given to the evidence that points away from the defendant’s involvement at the time of construction of this device. While there is some supporting evidence in this case in terms of association with violent republicanism and the defendant’s failure to give evidence, the weight to be attached to it in the circumstances of this case, does not in my view negate the evidence pointing away from the defendant’s guilt and casting doubt on the prosecution premise that the defendant’s DNA was deposited by primary transfer when the device was being constructed.
[99] In these circumstances while other circumstantial evidence may create the suspicion the defendant was involved in this incident, no matter how strong the suspicion, it is not sufficient to establish proof beyond a reasonable doubt and is insufficient to persuade me beyond reasonable doubt that the defendant was involved in the construction pertaining to the device.
Accordingly, I find the defendant not guilty on each count.
Sexual assault – DNA transfer – Probative value s 137 – Unfair prejudice – Evidence excluded
In 2018, it was alleged that the accused did sexually assault a female known to him by oral means. DNA samples were obtained and evidenced.
“It was my expert opinion that because the DNA profile cannot be attributed to a specific biological material, it is trace DNA”.
“Further, it was my expert opinion that the DNA evidence could be attributable to direct or indirect transfer”.
Judge Grant (2019);
[16] It is her [Helen Roebuck] opinion trace DNA can be transferred directly and indirectly. It is not possible to determine whether the DNA was deposited through direct contact with the vulval area, or whether DNA was deposited on to another surface and then transferred to the vulva…when individuals are in social contact or reside in the same property there is an increased opportunity of secondary and subsequent transfer of DNA.
[41] In DPP v Wise the Court made this observation at [70]:
“Moreover, one of the dangers associated with DNA evidence is what has become known as the ‘CSI effect’. The ‘CSI effect’ is a reference to the atmosphere of scientific confidence evoked in the imagination of the average juror by the descriptions of DNA findings. As we have explained, as a matter of pure logic, the DNA evidence has little or no probative value. By virtue of its scientific pedigree however, a jury will likely regard it as being cloaked in an unwarranted mantle of legitimacy — no matter the direction of a trial judge — and give it weight that it simply does not deserve. The danger of unfair prejudice is thus marked, and any legitimate probative value is, at best, small.”
[42] Having regard to the ‘CSI effect’ the jury would be tempted to place undue weight on the evidence which has almost no probative value.
[43] I refuse to admit the evidence sought to be adduced by the prosecution because if it does have probative value, which I very much doubt, that value is outweighed by the danger of unfair prejudice to the accused by reason of the possibility of misuse of the evidence by the jury.
Armed robbery – nolle prosequi - Hypothetical Prosecutor – s2 certificate granted
It was alleged that in 2019, the accused held up a Subway store at gunpoint, whilst wearing gloves and a hooded shirt. CCTV footage was inconclusive as to identity, however revealed that the offender had deposited plastic cable ties in the rear part of the store. DNA samples were obtained of the cable ties, resulting in the arrest of the accused.
“The cable ties returned a 3 person mixed DNA profile, with the evidence supporting the accused as a contributor”.
“The nature of the DNA profile was such that I could not determine whether the DNA was deposited by directly by the accused”.
Judge Coleman (2021)
[86] The Crown accepted that the DNA evidence was the most significant link in the chains (or strand in the cable) of its circumstantial case. That evidence showed the trace of the Applicant’s DNA as described above. It was a mixed trace with the DNA of two other contributors. It would be a significant matter in the mind of the hypothetical prosecutor when considering whether to institute proceedings.
[91] In my opinion, for the above reasons having regard to all of the relevant facts, I consider it was unreasonable for the proceedings to have been instituted.
[92] The application is allowed and I will make the orders sought.