When an officer is coded as 10-15, what does this signify?

The designation 10-15 in police communication signifies that an officer is en route with a prisoner. This code is part of the ten-codes, which are brevity codes used to communicate concise information over radio transmissions. The use of 10-15 allows officers to quickly inform dispatch and other units regarding the status of their transport without needing to send lengthy explanations.

Knowing this code is vital for maintaining situational awareness within the police force, ensuring that personnel and dispatch are informed about the movement of individuals in custody, which is critical for operational planning and safety. The other choices reflect different statuses or actions that do not pertain to transporting a prisoner, making 10-15 distinctly focused on the transport context.