What types of guns must all NCIC entries include?

The correct answer is that all NCIC entries must include serial numbers. This is essential because the serial number uniquely identifies each firearm, making it a critical piece of information for law enforcement agencies. It helps in tracking stolen guns, verifying ownership, and assisting in criminal investigations. The inclusion of serial numbers ensures that law enforcement can accurately differentiate between firearms, even if they belong to the same model or manufacturer.

While model numbers, owner information, and purchase receipts can also be relevant in various contexts, they are not necessarily mandatory for an NCIC entry. The serial number, however, is a key identifier widely recognized as essential for operational effectiveness in tracking and recovering firearms.