DNA Expert

Proffering rigorous, well-reasoned, and meticulously refined DNA expert witness testimony throughout Australia, and select international jurisdictions. Helen Roebuck is a strongly credentialed and highly regarded DNA expert within both the legal, and scientific communities. Leading Roebuck Forensics with over 20 years of service to the courts, assessing DNA evidence pertaining to literally thousands of indictable matters including murder, sexual assault, drugs importation, firearms and explosive devices.

Accepting instructions from criminal lawyers and directly from counsel, we deliver a robust evaluation of the DNA expert evidence, reliably identifying the true evidentiary weight as it pertains to the most current scientific theory and methodology.

Our authoritative DNA expert witness opinion is clear of obfuscation, explaining the most complex scientific scenarios in simple assertive terms. Terms that have proven to be readily understood and reliably favoured by juries and the courts alike.

DNA Expert witness

Our full spectrum expert forensic consulting service encompasses DNA, bloodstain pattern, biological fluids and STRmix. Drawing upon extensive international and governmental forensic biologist experience at crime scene investigations, laboratory procedures, and highly specialised expert witness evidence presentation before the courts. Roebuck Forensics’ depth of expertise spans the practical, technical, procedural, intellectual and jurisdictional.

With this breadth, we are remarkably well placed to assist the courts with serious matters incorporating crime scene assessment, sampling, testing, analysis, and review, such as they may be required, to form the foundation and contribution towards the preparation and presentation of authoritative DNW expert witness testimony.

Contact us

Case inquiry

Helen Roebuck


0493  726 760


GPO 390 Sydney NSW 2001

02 8089 0226

9am – 5pm GMT + 11hours

Published matters

  • R v Granaghan [2022] – N Ireland Crown
  • R v Perre [2021] – SA Supreme Court
  • LGBTIQ Hate Crimes Inquiry [2023] – NSW
  • R v Ke [2019] – NSW District Court 
  • Evans v R  [2023] – NSW Supreme Court
  • R v TAL [2019] – QLD Supreme Court 
  • R v Tsakirios  [2021] – NSW District 
  • R v Kabbout [2020] – NSW District Court

Roebuck Forensics

Murder – Bombing – DNA transfer – Crime scene officer contamination – False inclusion
R v Perre [2021] – Supreme Court South Australia

Murder – Bombing – DNA transfer – Crime scene officer contamination – False inclusion

The 1994 fatal bombing of the Adelaide National Crime Association implicating Domenic Perre, is one of Australia’s most sensational and longest running criminal matters.

After initially abandoning the prosecution, advancements in DNA science led to further investigation in 2016. 

“ I was instructed by defence counsel to review the forensic DNA evidence pertaining to the cloth, which was purportedly associated with the bomb manufacturing process. 

Prosecution intended leading scientific evidence in an effort to prove that Domenic Perre’s DNA was on the cloth.

With a precise interrogation of the DNA profile, I established support for the crime scene officer and Mr Perre’s brother within the profile.

I defined the identification of Domenic Perre within the mixed DNA profile as a false inclusion.

In response to my report and opinion, the prosecution proceeded to trial in 2018 in total absence of this expert DNA evidence.”

Firearms – Drugs supply - DNA transfer –  Crime scene officer contamination - Not guilty
R v Kabbout [2020] – District Court New South Wales

Firearms – Drugs supply - DNA transfer – Crime scene officer contamination - Not guilty

Charges alleged that in 2017, the defendant did possess a handgun and a supply quantity of class A drugs, which were seized within a vehicle owned by the defendant, whilst the vehicle was occupied by two other persons.

“ I received instructions to review the DNA expert evidence, along with a file that included body worn camera footage of the initial police vehicle search.

A review of the footage revealed that the crime scene officer did handle various items within the vehicle relevant to the DNA evidence, without thorough anti-contamination procedures.

The DNA sampling of the gun and drugs revealed mixed DNA profiles, of which the accused DNA contributed to pistol grip sample.

Following scrutiny of the relevant evidence, I formed the opinion that the DNA evidence did not contribute significantly to the prosecution version. 

The DNA expert forensic evidence was significantly ventilated at trial.

Judgment- Justice Buscombe;

114 : I am not satisfied beyond reasonable doubt that the accused possessed the cocaine.

109: I am unable to place any significant weight upon the findings of the accused’s DNA that was found on the guns grip

(1) Accused found not guilty in relation to all counts on the indictment

Legal Industry Speaking

Legal Industry Speaking

Our director and forensic DNA expert Helen Roebuck is a regular contributor to the legal profession, accepting invited speaking roles throughout Australia.

DNA evidence is critically relied upon within the criminal justice system like no other forensic science throughout history.

Legal practitioners across the profession, seek knowledge regarding DNA and its contribution to the judicial process, as DNA analysis continues to evolve.

These speaking events serve the legal profession well, whilst also providing me with valuable engagement that offers a greater understanding of the legal communities further needs and expectations of forensic biology and expert evidence” 

Law Institute of Victoria criminal law conference

  • 26 July 2024

Marbury Chambers - Bespoke event

  • 30 March 2025

international association of forensic scientists– Symposium

  • 22 November 2023

South Australia bar association -  Bespoke event

  • 19 March 2024

Law Society Tasmania – criminal law conference

  • 1 March 2024

Law Society Queensland – Symposium

  • 8 March 2024

Frequently Asked Questions

How much does a DNA expert cost?

DNA expert Helen Roebuck proffers carefully refined DNA evidence for rates which are comparable to those of a skilled and experienced criminal lawyer.

What is a DNA evidence report?

A DNA expert report authored by Helen Roebuck, will evaluate the crown evidence, biological casefile, relevant documentation and consider the weight of both the prosecution and defence versions. The detailed written expert evidence will follow a clear progression of evidence gathering, evaluation and careful formulation of authoritative opinion.

How long does DNA expert opinion take?

Under our normal processes, we can generally complete a preliminary review within a week and a DNA expert report in 2 to 4 weeks. Matters before the courts can be turned around on an urgent basis, depending on our casework load and the complexity of the matter.

Does legal Aid funding cover DNA expert evidence?

We are regularly instructed by Legal Aid lawyers and private lawyers with legal aid funding in the service of DNA expert evidence. Our current experience in 2024 is that legal aid funding is not a significant obstacle.

Can we handle matters all over Australia?

Helen Roebuck has extensive and intimate knowledge of the procedures and practices of each and every governmental laboratory throughout Australia. To the extent of familiarity with many of the experts by name and their courtroom manner.

Evidence is regularly provided by Audio Visual Link as well as by way of personal appearance in any state of Australia.

Do we take instruction on DNA matters outside Australia?

Originating from 2001 training at the Forensic Science Service in the UK, Helen Roebuck has been called upon to provide forensic expert opinion in the United Kingdom as well as New Zealand and the United States.

Acknowledgement of Country

In the spirit of reconcilliation, Roebuck Forensics acknowledges the Traditional Custodians of country throughout Australia and their connections to land, sea, and community. We pay our respect to their Elders past and present and extend that respect to all Aboriginal and Torres Strait Islander peoples today