Independent Forensic DNA Opinion for Criminal Proceedings
Forensic DNA evidence is often presented to courts as objective, definitive, and difficult to challenge.
In reality, its probative value depends entirely on how the evidence is interpreted, contextualised, and communicated.
Roebuck Forensics provides independent expert reports and court evidence for criminal proceedings, with a focus on forensic DNA and biological evidence.
Our reports identify the true evidentiary weight of the scientific findings, clearly explaining what can — and cannot — be supported by the evidence.
With matter-specific precision, our reporting assists criminal lawyers to guard against unsupported assertions and inappropriate inference at trial.
Forensic DNA evidence is often presented to courts as objective, definitive, and difficult to challenge.
In reality, its probative value depends entirely on how the evidence is interpreted, contextualised, and communicated.
Roebuck Forensics provides independent expert reports and court evidence for criminal proceedings, with a focus on forensic DNA and biological evidence.
Our reports identify the true evidentiary weight of the scientific findings, clearly explaining what can — and cannot — be supported by the evidence.
With matter-specific precision, our reporting assists criminal lawyers to guard against unsupported assertions and inappropriate inference at trial.
Independent Expert Evidence - Not Laboratory Reporting
Laboratory reports are necessarily limited.
They typically address what DNA profile was obtained, and whose DNA it may be, often stopping at the source level.
Expert evidence requires more.
As an independent forensic DNA expert, my role is to:
- critically evaluate laboratory findings
- assess the conditions of collection, handling, and examination
- consider alternative explanations for the presence of DNA
- distinguish source-level findings from activity-level propositions
- assist the court in understanding what the science can - and cannot - say
This independence is fundamental to reliable expert opinion.
DNA interpretation
- Review of single-source and mixed DNA profiles
- Assessment of likelihood ratios and statistical expressions
- Evaluation of whether statistics are limited to the propositions tested
- Assessment of assumptions underpinning probabilistic genotyping (including STRmix™ outputs)
Activity-Level DNA ASSESSMENT
- Evaluation of whether DNA findings support alleged activities
- Consideration of direct, secondary, and tertiary transfer mechanisms
- Assessment of persistence, background DNA, and contextual relevance
- Identification of alternative explanations not addressed in reporting
Evidence Collection & Handling Review
- Review of crime scene collection practices
- Assessment of exhibit handling and packaging processes
- Identification of investigator-mediated transfer risks
- Evaluation of post-collection DNA movement and redistribution
biological material and fluid attribution
- Assessment of whether DNA can be attributed to a specific biological material
- Review of presumptive and confirmatory testing methods
- Identification of unsupported fluid attribution
- Evaluation of limitations in biological source inference
Reliability, Weight & Evidentiary Limitations
- Evaluation of probative weight in context
- Assessment of factors affecting evidentiary reliability
- Consideration of low-level DNA, and mixture complexity
- Identification of interpretive assumptions and uncertainty
Court-Focused Expert Opinion
- Preparation of independent expert opinions for criminal proceedings
- Clear separation of scientific findings from legal inference
- Transparent explanation of strengths and limitations
- Opinions suitable for voir dire, trial, and appeal
Reports prepared for court, not just for scientists
Our expert reports are written the court.
They are structured to be:
- scientifically rigorous
- transparent in reasoning
- clear about limitations
- resistant to misinterpretation
- suitable for use in voir dire, trial, and appeal
Where appropriate, reports address the scientific findings in a manner consistent with legal principles, to ensure the court is not invited to draw inferences about the science that are not scientifically supported.
when expert evidence is most valuable
Independent expert involvement is particularly important where:
- DNA evidence is central to the prosecution case
- The case relies heavily on low-level or trace DNA
- Mixed DNA profiles are interpreted as highly incriminating
- Activity-level questions are being implied but not addressed
- Transfer, persistence, or contamination issues are present
- DNA findings appear strong statistically but weak contextually
Early expert input can assist in case strategy, evidentiary challenges, and identifying whether further scientific enquiry is warranted.
Instructing Roebuck Forensics
Instructions are accepted from criminal defence practitioners, prosecution agencies, and legal aid bodies across Australia, New Zealand, and select international jurisdictions.
Expert reports may be prepared at any stage of proceedings, including:
- appellate matters
- early case assessment
- pre-committal review
- trial preparation
Next Step
If you’d like to discuss whether the forensic evidence in your matter warrants further review:
A preliminary DNA expert review can be a useful step in assessing the broad strengths and weaknesses of a particular matter. This process can also identify documentary and any further evidence requirements.PE
Rigorous interrogation of the evidence will uncover underlying issues and determine the most appropriate pathway towards reviewing and reporting the matter.
Certain complex matters benefit from a draft DNA expert report, which can open areas for discussion with Counsel, and potentially allow for defence to approach the prosecution.
Following a thorough evaluation of the evidence, a DNA expert report will be issued in accordance with the expert witness code of conduct. The report will be suitable for submission in evidence.
Preparations with Counsel are often conducted, such that the probative value of the evidence is weighed effectively and persuasively at Voir Dire, should such a hearing be required.
Extensive preparations are generally conducted in anticipation of substantive hearing. Which may include cross examination and evidence in chief scenarios specific to the matter .
Professional Memberships
International Association of Bloodstain Pattern Analysts
The International Association of Bloodstain Pattern Analysts (IABPA) is a worldwide professional forensic organization for experts in bloodstain pattern analysis (BPA), promoting the science, standardizing techniques, and providing education to help investigators reconstruct crime scenes by interpreting bloodstain shapes, sizes, and distribution to understand the events, force, and weapons involved.
The IABPA unites scientists, law enforcement, academics, and criminal justice professionals to advance this field, which uses physics and biology to interpret patterns for court cases.
Australia and New Zealand Forensic Science Society
The AFS (Australian Forensic Society) was formed in 1971 to bring together scientists, police, criminalists, pathologists, and legal professionals actively involved in the field of forensic science. In 1988, the AFS recognised New Zealand members and changed its name to ANZFSS.
Australian Academy of Forensic Sciences
Chartered Society of Forensic Sciences
The Forensic Science Society was founded in 1959. Now accepting memberships globally the CSOFS is the peak professional body for forensic practitioners, academics, researchers and associated professions in the United Kingdom.
In 2014, the Society was granted a Royal Charter and became The Chartered Society of Forensic Sciences.
The CSOFS is recognised as the ‘international voice of forensic science’.
The Chartered body is committed to integrity and impartiality, aiming to provide opportunities for practitioners and academics to congregate, communicate and collaborate.
LAWYERS-DNA TOOLKIT
- 2 Minute DNA explainers
- 110+ scientific paper extracts
- Lab report explainers
- Scientific Guidelines