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GlossaryDispatch and call records

Duplicate call

A duplicate call is an additional record or report associated with an event already logged. Learn why duplicates are not necessarily false reports or simple data errors.

A duplicate call is an additional report or dispatch record associated with an event already recorded by the communications system. Several people may report the same crash, alarm, or other concern. “Duplicate” describes a relationship among reports; it does not mean the additional caller was mistaken, that the report was false, or that the information was useless.

More reports than events

Communications staff can use additional reports to clarify a location or add observations. Depending on the system, staff may add information to the first event or create a separate record and link it later. These approaches leave different traces in a public export.

San Francisco's documentation distinguishes reports grouped under one CAD number from separately created dispatch records later associated through a duplicate-reference field. It also warns that those associations are operational and may be incomplete. San Francisco duplicate-record explanation

The relationship matters when counting activity. A telephone-contact total, a dispatch-record total, and a count of underlying events can differ even when each is calculated correctly. Removing all repeated-looking rows without identifying the record structure can erase real information.

Example

Hypothetical example: Two callers report a traffic signal hanging over the same intersection. Separate call takers initially create events A101 and A102. Staff then associate A102 with A101. The second caller adds that one lane is blocked, information the first caller did not provide.

A raw export could contain two call records. A documented count that groups the linked records could treat them as one event. Both callers contributed to the response, so the second report still represents communications workload. The identifiers and field behavior in this example are illustrative.

Common confusion

A duplicate call differs from a duplicate database row, which might be an accidental repeated copy of the exact same record. It also differs from a repeat incident at the same address. Two alarms at one building on different days can be separate events.

Matching locations and call types alone cannot establish duplication. Nearby incidents can occur close together in time. A narrative may explain a relationship that a short public table does not show.

Identify the agency's linking field and whether it is reliably populated. State whether a total counts original records, all linked records, incoming contacts, or grouped events. Preserve a record of the method so the result can be reproduced. A missing duplicate link should not be treated as proof that a record concerns a wholly separate event.

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