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Concerns about how police process CCTV images for the courts

By Peter Webster, director of the CCTV User Group

We recently attended the National CCTV Conference 2022, hosted by the National Police Chiefs’ Council (NPCC). Held in Bristol, it was an opportunity to learn more about what happens to CCTV after it leaves the CCTV control centre.

It was a fascinating conference, but some of what we saw raised questions and concerns about the way video is edited and packaged for presentation in court.

Bristol was the scene in June 2020 when a statue of Edward Colston, a 17th Century slave trader, was torn down by protesters and dumped in Bristol harbour. In December 2020, four people were charged with criminal damage. Appearing in court in March 2021, the four pleaded not guilty. Nine months later, in December 2021, the case went to trial. On 5 January 2022, the four were found not guilty by a majority of 11 to 1.

A presentation by the Avon & Somerset digital video unit (DVU) on court presentation methods focused on the Colston case and how video evidence was packaged and presented to the court.

Our concern is that the onus is being placed on the police to choose what to put in. And the default position is to put in only what supports the prosecution.

What they said was that in court cases today, it is not enough to present the video clips as is. Juries want an edited video presentation with a storyline which is what the DVU delivered in the Colston case.

Watching the video at the conference, Ilker Dervish (CCTV User Group vice chairman) and I were both struck by how sophisticated the video editing was, like a TV programme.

It was very impressive, but we are concerned that it’s also very selective. It’s as if the police were putting together an evidence pack to support the prosecution rather than simply providing best evidence.

According to the conference presentation, the Crown Prosecution Service (CPS) will not accept video product that is not clipped and redacted.

Our concern is that the onus is being placed on the police to choose what to put in. And the default position is to put in only what supports the prosecution.

The net effect is it potentially bypasses the disclosure process and could possibly leave out some useful information that may benefit the defendant.

Our concerns are not just limited to the Colston case. In the view of the CCTV User Group, this raises further concerns about the police video evidence platform, DEMS (Digital Evidence Management System).

We have been concerned about DEMS for some time, as we consider it to be a poorly thought out solution to a complex problem.

DEMS works best for video which has been clipped to keep the file sizes down. In addition, the police expect the video to be redacted – that is, faces and other identifying imagery that is not related to the case should be blanked or blurred out. And ideally they want it in storyboard format to make it presentable in court.

But this runs the risk of only telling one side of the story. In the case of a low-level crime, where the defence possibly won’t pursue full disclosure, the result is that the prosecution and defence only get what the police give them.

When I was CCTV manager at Slough, we had a policy that we would not use DEMS. Police would be required to come into the control room and sit with a CCTV operator who could guide them through what video evidence had been captured. Often a knowledgeable operator can point police to camera views that they hadn’t thought of, cameras which might provide better evidence or a more complete picture of events, even if that supports the defendant. The conversation between the investigators and the operators who captured the original evidence, especially in the case of serious crime, is critical in making sure police get the best evidence available.

Another interesting discussion at the conference in Bristol was that of ‘what is a Master copy’?

One of the reasons I refused to work with DEMS in Slough was that this system fails to secure and store a Master copy of the captured and un-transcoded video evidence. This is why: In order to prepare the master video for use in DEMS, the native recording system has to transcode it from the proprietary NVR format into one that can be accepted by DEMS.

However, when uploading it into DEMS, it re-transcodes the video on ingestion into a suitable format for police use. Therefore, in my view, where this takes place, the video provided to police cannot be considered a Master copy as it has been transcoded twice and likely to have had the quality reduced.

Lastly, procedures mean that any video uploaded to police makes them the Data Controller and therefore required to retain a Master copy but, of course, they don’t actually have a master copy and neither do the originators as they will have deleted the master after they uploaded it into DEMS.

While having a chat at the conference, someone posed an interesting question about DEMS type systems. The person said to me, if I have an original Picasso masterpiece hanging on my wall and I take a photo of it with my phone, do I now have two masterpieces? If I print the photo I took with my phone, do I now have 3 Picassos? If I fax the printed photo to my wife and she makes 100 photocopies, do we now have 103 Picasso’s? No, of course we don’t.

However, the conference was certainly well worth attending. It was an invaluable opportunity to understand what happens to CCTV evidence on its way from a crime taking place to a decision being handed down in court.


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