Final answer:
Sergeants are generally expected to report serious incidents such as felonies and violent crimes to Watch Commanders, but specific crimes that require reporting before the end of a shift depend on department policies.
Step-by-step explanation:
When considering what crimes a Sergeant must report to a Watch Commander before the end of their shift, the correct procedure will vary depending upon the police department's policies and protocols. However, commonly, Sergeants are expected to report a range of incidents, particularly those of serious nature, which often include felonies, violent crimes, and significant misdemeanors. For instance, violent crimes such as homicides, sexual assaults, robberies, or aggravated assaults are typically given high priority and must be reported promptly. Still, the requirement can encompass other types of crimes and incidents as stipulated by department policy or legal requirements. Due to the lack of context about the specific policies of the involved police department, the most accurate answer cannot be provided without further information.