Block on Trump's Asylum Ban Upheld by Supreme Court
If the idea of a sheriff rounding up a bunch of citizens to hunt down criminals sounds antiquated, that's because it is. While perhaps necessary in a wild west lacking established law enforcement institutions, we generally leave the matters of search, arrest, and punishment to the professionals now.
So it may surprise you to learn that there are modern day sheriff's posses, still operating in the much-less-wild west, although you probably won't be surprised to learn who is in charge of "America's largest volunteer posse." That would be the infamous Maricopa County Sheriff Joe Arpaio, whose cold-case posse determined that Barack Obama's birth certificate was fake and whose deputies have been warned repeatedly by courts to stop racially biased policing and ad hoc immigration sweeps.
So how much authority does the Maricopa County Sheriff's Posse, and others like it, really have?
My Posse's on Broadway
Posse comitatus, or "power of the county" once referred to males over the age of 15 who could be called into service by a sheriff. It was shortened to just posse on the American frontier, where most of our modern conceptions of a posse come from -- armed men on horseback, riding down cattle rustlers, bank robbers, and other outlaws. This classic form of posse largely gave way with the rise of incorporated cities and their own police departments.
Many states still have modern posse comitatus statutes, like Kentucky's law that gives any sheriff the power to "command and take with him the power of the county or a part thereof, to aid him in the execution of the duties of his office." And in 1977 the Aspen, Colorado, sheriff called out the posse comitatus to hunt for escaped serial killer Ted Bundy.
The majority of modern posses are ceremonial in nature. Napa and Ventura County posses note their involvement in parades and shows of support for law enforcement, though members may volunteer for search and rescue aid. Sheriff Arpaio's posse, however, seems to take a more active role in policing.
Members of the Maricopa County Sheriff's Posse, some of them armed, spend anywhere from 10-40 hours per week on patrol, which can include "checking on empty houses whose owners are away, directing traffic after an accident, offering water or a lift to an old person walking in the sun (people with dementia often wander), consoling a crime-victim whose cash was nabbed from a purse left by an open door, or quizzing homeless people loitering on a local nature trail." They also have a fundraising drive, buying new $6,000 police radios or their own $40,000 black and gold patrol cars.
Even turning the flashing lights on one of those cars on, however, can be dicey. Posse volunteers can only volunteer their services, and pulling cars over, making arrests, and even turning on the siren without direct orders from a sheriff's deputy is prohibited. That said, Arpaio seems all too happy to enlist his posse's help. "I don't just send the posse out to rescue horses," he has said.