Should I get an independent DNA expert?

Where DNA evidence forms a significant part of an allegation, independent forensic review can be critical to understanding what the evidence actually shows — and what it does not.

An independent DNA expert does not repeat what the laboratory has already said. Their role is to examine how the evidence was generated, how it has been interpreted, and whether the conclusions drawn are scientifically justified.

This can involve reviewing the sampling strategy, the selection of exhibits, and whether important areas were not tested. It may include assessing the DNA profiles themselves, including mixed profiles, low-level DNA, or partial results, and examining whether the analytical approach used was appropriate.

Independent experts also evaluate statistical interpretation — including likelihood ratios, modelling assumptions, and how strongly results are presented. In some cases, different assumptions or approaches may materially affect how the findings should be understood.

Handling and contamination are further areas of scrutiny. An expert may examine collection methods, packaging, storage, and laboratory processing to identify opportunities for transfer or the introduction of DNA. They may also assess whether the strategy used to recover evidence could have influenced what was detected.

Importantly, an independent expert considers the evidence at the level of activity — not just source. This includes evaluating whether DNA findings fit with the alleged events, whether alternative explanations exist, and whether the scientific evidence has been overstated.

Independent review can assist legal teams by clarifying the strength of the DNA findings, identifying limitations, highlighting issues requiring further testing, and, where appropriate, supporting challenges to how the evidence is relied upon in court.