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Diary of a drug expert witness

Published on 30 May 2023
Written by Rob Hood, Drug Expert Witness Coordinator
Rob Hood shares a typical week as an expert witness in drug investigations
Going equipped
3 mins read
Rob Hood, Drug Expert Witness Coordinator

Following a 30-year police career, mainly as a detective within the world of serious and organised crime, I am now a drug expert witness coordinator in Thames Valley Police (TVP).

Our team of four full-time coordinators are all members of the national Drug Expert Witness and Valuation Association (DEWVA) group. Every drugs investigation with an element of supply involved can require a drug expert witness report.

This is a snapshot of my ‘typical’ week.


Having received a court warning last week, I am at Reading Crown Court, presenting my drug expert witness evidence in a multi-handed cocaine supply trial. I comment on an array of phone downloads and the valuation of drugs seized.

Although employed by TVP, I am independent of the investigation and engage with both prosecution and defence barristers to see whether there is any further material they want me to consider. I must remain impartial and simply seek to assist the court in understanding the drug evidence, not to assert guilt, which is a big change from when I was a police officer.


A continuing professional development day for the team has been arranged with the Crown Prosecution Service. We use a vacant magistrate’s courtroom at Oxford Magistrates Court and replicate the process of delivering expert evidence in front of a judge, including evidence in chief and cross-examination.

While travelling home, I receive a call from TVP’s Serious and Organised Crime Unit. They have just arrested a subject, seizing three kilograms of cocaine and a significant sum of cash. To assist in the remand of their subject, they need an urgent, abbreviated report that covers the circumstances of their investigation and the valuation of the drugs seized. They are hoping to go to CPS for a charging decision, so they have asked for this report within two hours. The full report, covering the entire investigation, will be completed at a later date.


An office-based day catching up with the numerous reports, which contain my opinion around phone messages, including slang terminology for types of drugs, as well as quantities, circumstances of investigations and valuations of drugs seized.

Within TVP and across the region, we regularly update each other about current drug prices, from wholesale, mid-market to street level of supply, as well as engaging with the National Crime Agency for national trends. Most of these updates are obtained from current investigations where prices have been discussed within phone communications or from intelligence reports. Each report is unique and could take anywhere from a couple of hours to a number of weeks to complete.


It is the county lines intensification week in TVP and we have offered assistance with any pre-planned activity, as well as any urgent reports.

I’m going on a warrant to a suspected cannabis factory, to guide and advise the resolution team on site. This gives me first-hand experience of the professionalism of the setup within the address, enhancing my knowledge when I come to prepare a DEW report on the investigation.

I am also on standby to assist another investigative team, following a warrant at an address where a dedicated drugs line phone from the West Midlands has been located.


Back to the day-to-day role of reviewing any incoming requests for DEW reports, allocating these out to the police officers who have the DEW role as a secondary skill and completing my own reports. We have between three and five requests every day for a report, ranging from low-level street supply to complex conspiracies involving organised crime groups.

The afternoon brings a call from a colleague within the South East Regional Organised Crime Unit, who wants to discuss a potential report based on phone conversations obtained from a prison establishment. Having reviewed what they have obtained, it is highly likely that an official request for a report will follow!

A long but good week and, with the DEW Cadre within TVP receiving around 600 requests per year for reports, it’s likely to be busy again next week!

  • This article was peer reviewed by Detective Sergeant Mark HIbbert, West Yorkshire Police
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