When is it appropriate for Sergeants to relieve Patrol units?

The correct choice emphasizes the procedural aspect of relieving patrol units, which is typically done after the next shift's roll call. This ensures a smooth transition between shifts while maintaining accountability and continuity in operations. By waiting until after roll call, Sergeants can ensure that all appropriate briefing has occurred and that the handover of any ongoing duties and responsibilities is conducted efficiently. This practice helps avoid gaps in coverage and ensures that incoming officers are fully briefed about any ongoing situations.

Other scenarios, such as after major incidents, may warrant a change in deployment but do not serve as the standard protocol for routine relief of patrol units. Relieving units based on the number of pending runs or without proper approval from the Chief of Police could lead to mismanagement of resources, potential lapses in response times, or violations of department procedures.