David Jarratt-Knock BSc (Hons), MCSFS


Area of Expertise


Forensic chemistry >


Shoe prints and footwear mark comparison

Tool and manufacturing marks


Trace evidence



David is a highly experienced forensic scientist specialising in footwear, tyre tracks, other impressed marks, and
alcohol technical defence. He has worked as a forensic expert in both public and private sectors, and has reported on hundreds of cases for both the prosecution and the defence. He has given expert evidence on numerous occasions in Crown and Magistrates courts across the United Kingdom.



  • Highly experienced expert in footwear marks casework, including complex cases such as those involving injury marks on bodies.

  • Highly experienced expert in alcohol technical defence (ATD) casework; performing and reporting on calculations relating to blood and breath alcohol concentrations of those involved in Road Traffic offences (back calculations, hip flask or statutory defences, laced drinks).

  • Expert in tyre track evidence, glove marks, tape comparisons and physical fits

  • David has delivered many hundreds of cases across all disciplines for police and the defence

  • Designed and delivered training programmes to police and internal staff

  • Experience of forensic procurement programmes

  • BSi-trained quality auditor, having carried out numerous audits across a range of forensic disciplines to support ISO 17025 accreditation in both public and private sector laboratories.

Committee Memberships

  • Member of Skills for Justice Working Group on National Occupational Standards in forensics

  • Member of AFSP Working Group on Case Assessment and Interpretation

  • Member of the Chartered Society of Forensic Sciences, and the International Association for Identification

  • Registered Forensic Practitioner in footwear marks for the Council for the Registration of Forensic Practitioners (CRFP), prior to the closure of CRFP in 2009.

Notable Cases

  • The Ding Family murders
    David attended the scene and reported on enhancement and recovery of footwear marks.

  • The murder of Olegs Sergejevs and attempted murder of Denis Segodins
    David reported the footwear evidence and gave court testimony

  • The murder of Craig Hodson-Walker
    David worked for the defence to conduct an examination of footwear


Forensic Equity is one of the UK's largest providers of independent forensic science services.

Our mission is to ensure that fair and impartial forensic science is accessible to all.

 With some of the most experienced scientists in Europe, our clients can be safe in the knowledge that they are benefiting from an unrivaled source of  expertise and the most robust scientific reporting.

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“I wanted to thank you and your team for the amazing efforts, work and speed with which you attended to the various queries that arose during the trial. After only 4 hours, the jury unanimously acquitted ‘M’ and convicted the co-defendant.

I personally am very grateful, especially as it made my task of dealing with certain issues easier and more professional.”

Barrister, Furnival Chambers


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