To say that this (Figure 1 below) is exactly what the CCTV User Group have been saying for such a long time would be an understatement.
Finally, we have appropriate guidance that respects the long-held view that the 'Master copy' of captured video evidence must be secured & protected (not redacted or transcoded) and that only a 'bit for bit' duplicate of a Master copy (the Working copy) can be used for forensic analysis.
The guidance goes on to state:
'Within the area titled Working Copy [see below], the first item is identified as a bit-for-bit duplicate, the only route to forensic analysis is from this item. Below bit-for-bit duplicate and slightly separated from it are 3 examples of files that could be labeled ‘Working Copy’, these are Processed, Court Playable and Redacted. None of these have a link to forensic analysis, and all carry the caveat that they must be renamed and uniquely identifiable.'
Procedure and supporting guidance to help police forces prepare their own policies for retrieving native video and audio from CCTV systems.
'Closed circuit television (CCTV) is commonplace in our society and has proved to be an invaluable tool in the investigation of crime ranging from petty theft to terrorism. However, the proliferation of different CCTV systems, together with the transition from static to cloud based systems has required a change in practices for the recovery and processing of video evidence. This is particularly evident in the increased level of technical knowledge required for retrieval of video evidence from the diverse range of CCTV systems in use.
It is therefore vital that the police have clear procedures and guidance to follow when retrieving video and processing images from digital CCTV systems, and maintain the integrity of the evidence.
We are confident that this procedure provides a sound framework within which to effectively gather and present evidence from CCTV systems.
Jenny Gilmer Assistant Chief Constable South Wales Police Chair, National Police Chiefs’ Council CCTV Working Group'
We strongly recommend that you read this guidance and train your teams in how to follow it.