Interview with Forensic Video Analyst David Spreadborough


What is your field of expertise and what does working in this area involve?

I am a Forensic Video Analyst. In short, the forensic analysis of video involves the scientific examination, comparison and/or evaluation of video in legal matters. That though really only tells half the story. Video now comes from a multitude of sources and probably only a quarter of those could be classed as standardized. Most have some sort of proprietary nature, designed by the brand or manufacturer of a specific product. You probably think immediately of Video from surveillance systems; CCTV. However, there is also personal recording devices such as smart phones, digital cameras, body worn video and dash-cams. The majority of these are now digital and sit within the category of Digital Multimedia Evidence (DME). With CCTV, most still actually start off as an analogue video signal from an analogue camera and then the digitization gets done further down the line.

Many people have attempted to guess how many different types of digital video there are, with figures stretching from 3000 – 5000! As you can imagine, this then means that every job starts as research. Manufacturers of CCTV systems can change the format of their recording every time they upgrade that model of Digital Video Recorder. Same make and model number, but who knows how the digital video is encoded, stored and then decoded for playback.

It is imperative that the digital data is dealt with correctly. If not, it’s like the contamination of a piece of traditional evidence. If it is contaminated, any interpretation and/or enhancement of that footage could be questioned. Acquisition of the media comes first and this can be the most challenging part when it is stored inside a proprietary Digital Video Recorder. You can’t just ‘pull the drive’ and extract the data like Computer Forensics. Many machines don’t even store the data in a standard way. Then after acquisition, the playback and processing of that data is a minefield of contamination opportunities. If the video is processed incorrectly then the possibilities could be limited.

Identifying the correct method of acquisition, in order to preserve the integrity of the digital data is the start of my job. I can then ensure that it can be used effectively. From here comes the interpretation but I need to understand how it was originally captured and encoded. If I am to make a decisions based on what was recorded, I have to take these factors into consideration. To assist in my analysis I may need to conduct restoration and/or enhancement of the footage using digital image processing techniques. When the video has been understood and processed within a forensic workflow, I am able to prepare that footage for comparative analysis or presentation. All of this has to be conducted in a manner that is repeatable and acknowledged by the community.

How did you come to be involved in this line of work?

I had been a Police Officer for 12 years, 6 in the Met and then 6 in Cheshire. As a tutor constable, I became frustrated over the methods and processes involved when dealing with CCTV evidence. As a result I put forward a suggestion to my Divisional DI with a solution of how CCTV could be dealt with, not only more effectively, but with higher evidential integrity. I already had some understanding of digital video so the initial stages were made a little easier. Within a few weeks, one of the first Divisional CCTV Units in the Country was started. That was back in 2003, and although technology has brought about huge change and increased our capabilities, the reasons why I started that unit remain. With the increased reliance on video evidence, but with limited budget and resources, those reasons are actually more important today.

What do you think is the most common misconception about your field of work?

“It’s just a Video”.

“Don’t do it that way, it takes too long”.

“Don’t worry about it, it’s only a DVD”.

“Just press, ‘Print Screen'”.

Senior Officers and Managers see how easy it is to stick a dancing cat on YouTube and then, for some unknown reason, apply that logic to evidence. Evidence that is controlled by guidelines and law. You can’t cut corners with evidence. The misconception comes from how easily video and images can be manipulated. It is the analyst’s responsibility however to ensure that the media is interpreted correctly and all processing is completed adhering to the rules of evidence. When corners are cut in order to speed things up and balance the spreadsheet, that’s when things can go wrong. It’s not just a picture or a video. It is evidence and should be treated as such.

When CCTV is dealt with correctly, the value stretches throughout the Criminal Justice System. From recognition intelligence through to impactive evidence used to exonerate or convict. I have heard some managers class CCTV as ‘Low Yield’, referring to the fact that they regard the expense of a Forensic Imaging Unit as needless. It’s a classic case of ‘you get out what you put in’. If you don’t invest and use the full capabilities available, it’s common sense that you won’t see the results.

Do you think the field of forensic video analysis in the UK has been affected by the recent changes to forensic science services?

It was a really tough decision to leave the Police after 24 years of service. I did so though because I care. I cared about the quality of my work. I cared about doing it right. I cared about making the right decision. It’s only been a few months so it’s a little difficult for me to answer with personal experience.

What I can say though, is that in both the Police and private sector there is pressure now to ‘dumb it down’. Ensuring that more can be done for less. Rather than understanding what the evidence is, and how it should be processed, pressure is put on technicians to get the jobs done. I have seen countless examples where incorrect processing has been completed, resulting in images and video being presented that are not a true and accurate representation of the events captured by that camera. I have seen many comparative analysis reports where the images being used have not been created correctly according to the Digital Imaging Procedure. I have seen Video presented that has been acquired by methods not even mentioned in the Home Office Guidelines for Retrieval of CCTV.

Some of these issues end up causing further delays to an investigation. If I receive a disk from a solicitor, and am under instruction to analyze the footage, there is often disbelief when I re-contact to state that it is not the original evidence. They then have to request the original evidence and the whole process starts again. The introduction of standards in Forensic Video Analysis through ISO will help, but we are a long way off.

The majority of Forces invested when the FSS closed, ensuring that only the most complex or time consuming tasks required out-sourcing to the private sector. A few of the Forces, with experts in-house, were also able to make the correct decisions on out-sourcing as they knew the technical possibilities involved and the expected results. With current budgetary restraints within the legal system, this is reversing. Forces just have not got the money or the staff do the jobs anymore.

Do you think the specialty of forensic video analysis is currently being utilised to its full potential?

Not at all. Well, actually there are one or two places in the UK where it is given the respect, and then the funding, that it requires but there are many places where it is simply not possible to develop, due to a lack of joined up thinking. There are many facets to DME and Forensic Video Analysis. When a number of these get linked, then everybody wins. From reviewing CCTV during a major incident, the recovery of data, the use of Social media for intelligence… I could go on.

I go back to my answer earlier, when I stated that I have heard it called ‘Low Yield’. Think of a field of Barley. Left alone, it will produce a bad crop with a low yield. Invest the time and effort and you will get a good crop, with a high yield. To fully reach its potential, you need someone who knows what they are doing and is prepared to invest.

Do you have any advice for those wishing to follow your career path?

It’s an unknown world to most! People often think that video is just moved magically across networks and ‘it is what it is’. As a result, it’s one of those jobs that you don’t really know exist. It is also a very small, niche sector of Digital Forensics. All the kudos and media navigate to anything with Cyber and Security in the title… Forensic Video Analysis is tucked away! You do see the jobs advertised every now and again, within Police Forces and also within the Private Sector Forensic services.

Enthusiasm, a willingness to learn… and then learn some more, along with a ‘never give up’ attitude. Investigating proprietary video can be extremely frustrating. That was one of the reasons why I started my blog over 6 years ago. I needed a way to document some rather lengthy processes and in doing so help others. I strategically left the comments enabled so people could add in their solutions to problems. I quite often have to go back and carry on research with a file first encountered three years ago!

Always ask questions of the video. Look beyond the image to understand how that video was constructed. Only then will you be able to interpret that video correctly. Will the compression affect enhancement? If you don’t understand the compression – are you enhancing artefacts that were never present in the scene? A lot of young people now come to it through traditional computer forensics. Some people through digital imaging and photography. Whatever route is taken, never be afraid to ask for help. The worldwide community is pretty small but with some very great people. It is rare to come across something that someone else has not encountered before.

The career will take you from just attempting to get a video to play (easier said than done sometimes), through a multitude of tasks and requirements. You could end up doing 3D Laser scanning of scenes and overlaying the CCTV Footage with aerial footage from a drone. You could end up data carving huge amounts of video and reverse engineering the embedded timecodes. You could end up conducting advanced Digital Imaging techniques to enhance details in a video not originally view-able.

If you enjoy working with digital media and want to be challenged every day, then Forensic Video Analysis may be something to look at… (excuse the pun!).

Is there anything else you’d like to add?

FVA is now part of me. It’s who I am. It’s not just a job or a career…. it’s my passion. Every case is different and requires thinking. This is not in the ‘Push Button Forensics’ domain.  It’s been a pleasure being interviewed and I hope that it has opened up a few people’s eyes to the world of FVA.




If you’re a forensic scientist (academic or industry) or a crime scene investigator and would like to be part of this series of interviews, get in touch by emailing locardslabblog[at]

This is Part 5 of our series of interviews with forensic professionals.

Interview Series Part 1 – Interview with Forensic Identification Scientist Alexandre Beaudoin

Interview Series Part 2 – Interview with Forensic Expert Robert Green OBE

Interview Series Part 3 – Interview with Forensic Expert & Consultant Gareth Bryon

Interview Series Part 4 – Interview with Forensic Identification Specialist Donna Brandelli