The line of authority is the line of jurisdiction. That is sometimes as simple as "within the city limits" and "unincorporated areas of the county."
For example, David, since you and I both know Los Angeles well, the LAPD is responsible for the city limits of L.A. That's everything in purple on this map:
View attachment 9570
The places not in purple are a mix of cities that have their own police departments (Santa Monica, Inglewood, Long Beach), and unincorporated areas of the county that are not within a city limit. Those unincorporated areas are in pink on the map below:
View attachment 9572
The L.A. County Sheriff's Office is responsible for law enforcement in the unincorporated areas.
But it's more complicated than that, because there are 40 incoprated cities in L.A. County that have chosen not to have their own police departments, but to contract with the Los Angeles County Sheriff for law enforcement within their city limits:
Again, though, the agencies know what's their jurisdiction and what's not and in a situation where LASO might be a block away from an emergency not in their jurisdiciton, mutual aid agreements allow them to respond.
They might be first on the scene, but as soon as the city police arrive, the PD assumes jurisdiction and thus control in terms of media access.
Beyond that, I just want to say that
@cc333 ,
@Weiserguy and
@Mediafrog+ all are correct, but there is one other distinguishing feature of County Sheriffs---they are elected officials.
Most city police chiefs are appointed by the City Manager, Mayor or City Council, but Sheriffs run for office. As
@Weiserguy pointed out, Sheriffs run the jails---and federal funding only goes up with the jail population, so many believe there is an immediate inherent conflict of interest. Incarceration benefits a sheriff.
County sheriff's offices are much more frequently targets of corruption and brutality investigations than municipal police departments. A CBS News investigation last year found county sheriff's officers are three times more likely to kill a citizen than municipal police officers:
More people were killed by U.S. law enforcement in 2023 than any other year in the past decade — and it's increasingly happening in small towns and rural areas.
www.cbsnews.com