Let's start from the beginning.  The
sheriffs have been the chief law
enforcement officers throughout the
United States since the 17th Century and
long before the formation of professional
police departments.  Today, the Sheriff
continues to be the top law enforcement
officer in most jurisdictions.

Theoretically, the Sheriff could take over
an investigation from a police department
if he or she wished since the Sheriff is an
elected official in contrast to a police
chief, police commissioner or
superintendent who are appointed to
their positions by mayors, city managers,
or governors.  I say theoretically,
because you won't see sheriffs interfering
with police departments.
What's the difference between a police
officer and a sheriff's deputy?
"What mayor wouldn't prefer having a
police chief appointed by that mayor
and serving at that mayor's pleasure
versus a sheriff elected in his or her
own right?" ~ Barry M. Baker
As a police officer anywhere in the
country, your law enforcement duties will
be uniform and wide ranging; whereas,
the duties of sheriffs' deputies may be
limited as to law enforcement
activities...or their duties may be identical
to yours.  For instance, you might be a
police officer with a county police force
where sheriffs' deputies in your county
are responsible only for the security of
court houses, prisoner transport, and
other general business of the court.  
Then, in the county bordering your
jurisdiction, that county has no police
department, and its sheriffs' deputies are
responsible for all law enforcement
activities to include patrol and criminal

Nearly all densely populated cities and
counties will have their own police
departments.  As the population thins
out, you'll see more smaller agencies
such as borough and township police
departments.  You might be in a small
township department where you're
supported by state police or sheriffs'
deputies.  In this scenario, the law
enforcement mission and duties of all are

The way sheriffs' deputies differ in their
law enforcement missions from police
officers is really all about politics.  What
mayor wouldn't prefer having a police
chief appointed by that mayor and
serving at that mayor's pleasure versus a
sheriff elected in his or her own right.  
While the mayor will have total control
over the chief, the sheriff, God forbid,
could be of the opposite political party.  
When an elected sheriff has the
responsibility for all law enforcement
duties within a jurisdiction, that sheriff
becomes a very powerful and politically
influential sheriff.

I've linked you below to a history of the
Las Vegas Metropolitan Police
Department.  This is an example of a law
enforcement agency labeled as a police
department and headed by an elected
"On July 1, 1973 the Clark County
Sheriff's Office and Las Vegas Police
Department were deactivated, and the
Las Vegas Metropolitan Police
Department became the official police
force for Las Vegas and the
unincorporated areas of Clark County.  
Sheriff Ralph Lamb took over as the
LVMPD head, with John Moran, former
LVPD Police Chief, as the Undersheriff."
Police and
Copyright © 2017  Barry M. Baker