Four Containers, Two Indicators: Testing an Informer's Claim
Four containers - A, B, C and D - are held at Karachi after a scanner review. Their declarations are: A ceramic tiles, B cotton textiles, C auto parts, D consumer electronics. The scanner flagged B and D but not A or C. A weight check showed that A, B and C matched their manifests, while D's actual weight exceeded the declared weight by 2.1 tonnes. An informer, whose earlier tips proved reliable but who is paid by results, states that exactly one container holds undeclared goods and that the contraband is not in a container declared as ceramic tiles. The officer also knows that a container fits the informer's description only if exactly one of the two indicators - scanner flag or weight mismatch - is present. A container with both indicators is treated as high-risk but does not fit the 'exactly one' rule.
1. Which container fits the informer's description? Show your elimination, not just the answer.
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Build a simple indicator table:
| Container | Scanner flag | Weight mismatch | Indicators present |
|---|---|---|---|
| A | No | No | 0 |
| B | Yes | No | 1 |
| C | No | No | 0 |
| D | Yes | Yes | 2 |
The rule requires exactly one indicator. A and C have none. D has two. Only B has exactly one. The informer's extra statement that the goods are not in ceramic tiles excludes A, but A is already excluded by the indicator rule; the statement is therefore consistent but redundant. On the stated facts, B is the container that fits the description.
That does not prove B contains contraband. It means B is the priority for a targeted examination. The conclusion is only as good as the rule and the underlying records, so the officer should verify the scanner log and the weighbridge record before acting.
2. How much weight should the informer's tip carry? Would your conclusion change if the informer were unpaid and had a grudge against B's importer?
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The tip is a lead, not evidence. A paid informer has an incentive to produce results, possibly by shaping or inventing information, so payment by results actually increases the need for independent corroboration. Past reliability supports credibility but does not prove this particular claim. Here the tip does not stand alone: the scanner and weight records independently generate the indicator pattern, and the officer can verify those records directly.
If the informer were unpaid and had a grudge against B's importer, the tip would be weaker as a motive-based accusation. The officer should then rely more heavily on the physical indicators and should not authorise an intrusive search on the tip alone. But B would still be a legitimate examination target because of the scanner flag, provided the examination is conducted lawfully and the reasons are recorded.
The key discipline is to separate the decision to examine from the decision to seize. Examination can be justified by risk indicators; seizure needs evidence from the examination, properly documented and open to challenge.
3. The scanner operator insists D must be the one because it is 'high-risk'. How do you respond?
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Acknowledge the concern but correct the inference. D has both a scanner flag and a 2.1-tonne weight excess, so it is genuinely high-risk and must be examined. But the informer's rule describes a container with exactly one indicator, and D has two. High-risk is not the same as matching a specific description.
There is also a practical risk in treating the puzzle as a substitute for examination. The logic narrows the informer-based lead to B, but D's weight discrepancy is a serious independent red flag that may point to an unrelated problem such as misdeclaration, concealment or a manifest error. The officer should not close D just because it fails the informer test.
The sensible plan is to examine B as the informer-priority container and D because of its own physical anomaly, recording separate reasons for each. If resources force a sequence, start with B but do not cancel D. The operator's certainty should be converted into documented observations, not allowed to override the rule.