Forensic Science and the Law

The main expert witness contacts in New Zealand are Dr Anna Sandiford and Ms Paige McElhinney with further additional skills from other experts including fingerprints, telecomms/cell phone data and forensic medicine.

Beyond those experts we have a team of national and international experts – please contact us to discuss further.

Our Responsibility

Impartiality, transparency and fairness are critical issues for the courts.  Our experts all know and adhere to the New Zealand High Court Rules: Code of Conduct for Expert Witnesses:


1. An expert witness has an overriding duty to assist the Court impartially on relevant matters within the expert’s area of expertise.

2. An expert witness is not an advocate for the party who engages the witness.


All of The Forensic Group’s experts, scientists and consultants are guided by at least the NZ High Court Code of Conduct and Ethics and many of our experts are governed by others that are set by professional organisations and the overseas forensic jurisdictions in which they also work.

Our Team

Dr Anna Sandiford

about an expert

or case

The Forensic Group was established in 2008 by Dr Anna Sandiford, a Senior Forensic Science Consultant with many years’ experience in New Zealand and overseas who started her forensic science career in 1998. Her expert witness history includes expertise in alcohol toxicology (particularly alcohol calculations), drug driving, drugs, footwear, glass, physical fits and pollen.  Since starting the company, Dr Sandiford has developed expertise in managing large and complex cases, having been involved in multiple high-profile cases including the 2009 Bain retrial, the 2015 Lundy retrial, the 2015 Privy Council decision of an unsafe conviction of Teina Pora for the murder of Susan Burdett, and many others.  She has been referred to as ‘the expert on experts’ and is author of Forensic Science and the Law: a guide for police, lawyers and expert witnesses (Thomson Reuters, 2013) and the general interest book Expert Witness (HarperCollins, 2011).


Dr Sandiford has extensive national and international networks from which to locate experts from across a broad range of expertise including rare and unusual skill sets. She has worked extensively with Legal Aid and the NZ Law Commission on issues relating to expert witnesses and forensic standards.

Paige McElhinney

about an expert

or case

Paige McElhinney has accumulated extensive casework experience since starting her expert witness and forensic science career in 2001.  She is an expert in application of scientific techniques to item and scene examinations including body fluid identification, blood stain pattern interpretation (scenes and items), fabric damage, using DNA results to assist with interpretations, hair comparisons, hair sample collection, physical fits, footwear and trace material recovery, transfer and persistence of biological and non-biological materials.


Ms McElhinney was part of the team that developed the medical examination kit and is co-author of the chapters on Forensic Specimens and Forensic Science and Drug Facilitated Sexual Assault in The Medical Management of Sexual Assault (Sixth Edition 2006), published by Doctors for Sexual Abuse Care.    She has also been contracted to the United Nations Office on Drugs and Crime to develop an Introduction to Forensic Science Course for a major overseas national authority.  Ms McElhinney has worked with the NZ Law Commission on issues relating to expert witnesses and forensic biological data management.

Thomas Coyle

Thomas Coyle has been a fingerprint expert for over 30 years and has considerable casework and crime scene experience.  He originally qualified as a Fingerprint Expert and Forensic Practitioner with the London Metropolitan Police at New Scotland Yard.  He has worked in New Zealand and overseas in a wide range of positions including Laboratory Manager at Auckland Fingerprint Section and also roles within anti-terrorism and as crime scene coordinator at major crime scenes.  He is a qualified Disaster Victim Identification Officer and has extensive experience collecting fingerprints and DNA in such scenarios, assessing identification using fingerprints and running scene collection teams.


He has now moved into the independent sector and undertakes examinations, re-examinations and interpretations and has skills and knowledge in enhancing blood prints at scenes in conjunction with DNA sample collection.

about an expert

or case

Dr Roderick Mulgan

Dr Mulgan is an experienced emergency medicine, general practice doctor and former police doctor.  He is also a qualified and practicing criminal defence lawyer. His consultancy roles within The Forensic Group are providing initial medical opinions on whether or not specialist instruction would be worthwhile and assistance with medico aspects of criminal cases.

about an expert

or case

Codes of Conduct and Ethics

Depending on the area of expertise, an expert witness may be governed by one or more Codes of Conduct and Ethics. The New Zealand High Court Code of Conduct for Expert Witnesses is the minimum standard we expect of any Expert Witness. We recommend that whether or not you use our services, you check with any individual expert witness which organisations and regulatory bodies cover their particular industry. Having a competent and appropriately qualified expert as part of the case team should be a priority in any case involving science or expert knowledge.