The Missing Evidence Bag
During an arrest at 22:15, an officer recovers a small plastic bag containing a white powder from a suspect's pocket. The officer places it in an evidence bag, writes the case number on the bag, and seals it. At 23:00 the officer realises the bag has no signature across the seal and no record of who handled it between recovery and arrival at the station. The suspect is being held and has not yet been charged. A colleague suggests simply signing the bag now and entering it into the log as if nothing happened. The station evidence log shows the bag was received at 22:50.
1. Identify the chain-of-custody problems in this scenario and explain why each matters.
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Problems:
- No signature across the seal - there is no proof the bag was not opened between sealing and receipt.
- No handler record between 22:15 and 22:50 - a 35-minute gap with no documentation of who had the bag or where it was.
- Back-dating the signature (the colleague's suggestion) would create a false record. That is not a clerical fix; it is fabrication of evidence and exposes the officer to disciplinary and criminal liability and could collapse the prosecution.
Why it matters: Chain of custody exists to show the item is the same item and has not been tampered with. A gap or missing seal signature gives the defence a clear basis to challenge authenticity, and courts may exclude the exhibit. The officer's credibility, and the case, are damaged more by a cover-up than by an honest report of the error.
2. Recommend the correct course of action and state how the officer should document it.
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Correct action: Do not alter or back-date anything. Report the defect immediately to the supervising officer and the investigating officer. Sign and date the bag now with a clear note that the seal signature was omitted at the time of sealing and is being added late, stating the time of the correction.
Documentation:
- A written statement describing recovery at 22:15, sealing, the discovery of the omission at 23:00, and the corrective step taken.
- An entry in the evidence log noting the late signature and the reason.
- Names of everyone who handled the bag and the 22:50 receipt time.
- Request that the exhibit be re-sealed or additionally secured with a fresh tamper-evident seal witnessed by a supervisor.
Principle: Transparency protects the case. A documented procedural error is far less damaging than an undisclosed one, and the suspect's rights and the integrity of the investigation are preserved.