Which ACPO principle requires an audit trail or other record of all processes applied to computer-based electronic evidence to be created and preserved, with an independent third party able to examine those processes?

• A. ACPO Principle 1
• B. ACPO Principle 2
• C. ACPO Principle 4
• D. ACPO Principle 3

Answer: (D)

This tests the requirement for auditable handling of electronic evidence with independent verification. In digital investigations, every action taken on the evidence—who did it, when, and what tools or methods were used—must be recorded in a traceable log. Preserving this audit trail and making it available for inspection by an independent third party guarantees the processes were followed correctly and that the evidence hasn’t been tampered with. This transparency supports the integrity and admissibility of the evidence in court, and it helps prevent bias or improper alterations during analysis. While other principles focus on preventing changes, proper authorization, or securing access, this one specifically emphasizes documented, verifiable, and reviewable processing by an impartial observer.