The integrity of the acquired digital evidence plays a predominant role in the digital process of forensic investigation. Proper chain of custody must include information on how the evidence was collected, transported, analysed, preserved, and handled. It must document where, when and how the digital evidence was discovered, collected, handled with, when and who came in contact with the evidence and whether it is altered in any way. If a link is missing in this chain, it could be deemed compromised and may be rejected by the court.
Any successful technical implementation does not necessarily warrant its admissibility in court. A strict and formal process needs to be followed, which can vary significantly among Member State, in order to make evidence, provided by a surveillance system, acceptable in court for the cause of prosecuting crime. Initially the device needs to be certified and controlled by the authorised crime prosecuting and investigating authorities, in order at first to be employed by them. Its findings need to be examined and cross-tested, in order to warrant their technical usability in court. Even more importantly, the relevant legal provisions need to be examined to ensure that such findings can be used as evidence and the recording procedure is completely transparent. In the court, all the technical data regarding the recorded data will need to be made available to the defendor’s legal side, in order to be able to be examined with their own technical advisors, and maybe contest their consistency, if applicable.