I have over 40 years experience as an expert witness, case reviewer, senior police manager, independent consultant, policy adviser and researcher. I have worked on thousands of criminal cases including and have extensive experience as an expert witness. Some notable cases include; the murders of Rachel Nickell and Damilola Taylor, the mysterious death of MI6 employee Gareth Williams, the Uk’s most prolific child murderer, Robert Black and the controversial conviction of Michael Stone for the murders of Lin and Megan Russell. 

I have also advised many public agencies on forensic, scientific and investigative matters, including police organisations in the UK and abroad, the Home Office, the Scottish Parliament and the UK Parliament.

I have published three books; The Handbook of Forensic (with Robin Williams), Forensic Science – a Very Short Introduction and Murder Under the Microscope – a personal history of homicide. I am currently working on a fourth book about expert evidence.