Which device is used to determine the number from which a telephone call originates?

Which device is used to determine the number from which a telephone call originates?

• A. Pen register
• B. Tracing device
• C. Wiretap
• D. Bug

Answer: (B)

To identify the origin of a telephone call, investigators use a tracing device. This tool is specifically designed to reveal the caller’s number by tracing the signal back through the telecommunications network, pinpointing where the call came from. A pen register, by contrast, records numbers dialed from the target line—outgoing digits—rather than who called in, so it doesn’t show the incoming origin. A wiretap intercepts the actual spoken content of the call, not the origin, and a bug is a hidden listening device placed somewhere to hear sounds, not to trace a call’s source. Therefore, the tracing device best fits the purpose of determining the number from which a call originates.

To identify the origin of a telephone call, investigators use a tracing device. This tool is specifically designed to reveal the caller’s number by tracing the signal back through the telecommunications network, pinpointing where the call came from. A pen register, by contrast, records numbers dialed from the target line—outgoing digits—rather than who called in, so it doesn’t show the incoming origin. A wiretap intercepts the actual spoken content of the call, not the origin, and a bug is a hidden listening device placed somewhere to hear sounds, not to trace a call’s source. Therefore, the tracing device best fits the purpose of determining the number from which a call originates.