But it's important not to jump to conclusions or generalize based on one case, said Jonathan Thompson, executive director and CEO of the National Sheriffs' Association. For departments across the country, he said, volunteer programs provide a lot of value.
"There are probably quite a few dozen, if not hundreds of programs out there," he said. "Let's not paint all of the success with the mistakes of one."
Here's a look at how some reserve programs work, and the reasons behind them:
Why do law enforcement agencies have volunteers?
Money, money, money.
Strapped police departments are increasingly looking to do more with fewer resources, and volunteer programs can help plug holes in their operating budgets, says the International Association of Chiefs of Police, which runs the Volunteers in Police Service program
"These budget shortfalls resulted in layoffs, furloughs, hiring freezes, loss of specialty units, cutbacks on training and equipment, and service cuts," according to an IACP study
Almost 2,200 law enforcement agencies utilized more 244,000 volunteers, the report said, adding that law enforcement volunteers have "become a need and not a luxury."
Do departments arm volunteer officers?
In the case of Bates, it's clear that the Tulsa County Sheriff's Office does. But like many aspects of volunteer policing, it varies from department to department.
For instance, in Orange County, Florida, they're armed. A reserve deputy must be a Florida-certified law enforcement officer and has arrest power so long as she or he is accompanied by a fully certified deputy.
"A Reserve Deputy has the same 'police power' as a full-time Orange County Deputy Sheriff, except they volunteer their services. Their uniforms are identical to an Orange County Deputy Sheriff and all necessary uniforms and equipment are provided," the program's website says
But in the New York Police Department, they have no guns, nor do they have any arrest power "beyond that of a private citizen."
"Equipped with a (two-way) radio and a baton, they are trained to 'observe and report' as they perform uniform patrol in their neighborhood as a crime deterrent," the NYPD's Auxiliary Police Program Overview says
What sort of training do they receive?
Another tossup, depending on the precinct.
In Oklahoma, reserve officers -- who may or may not be paid by their agency -- are required to attend an academy and get 240 hours of training, said Laurie Schweinle, spokeswoman for the state's Council on Law Enforcement Education and Training. The academy for full-time officers is 583 hours, she said. There are more than 3,500 active reserve officers and nearly 10,000 full-time officers in the state. Both groups, Schweinle said, have full police power.
The Tulsa County Sheriff's Office has three levels of reserve officers; Bates was at the highest "advanced" level, officials said. He'd been a reserve deputy since 2008, with 300 hours of training and 1,100 hours of community policing experience.
But, examining various law enforcement agencies across the nation, the extent of training runs the gamut. In Hennepin County, Minnesota, prospective reserve deputies attend a 10-week school that meets once a week for three hours a night in the spring.
In Riverside County, California, there are tiers: Level III reserve deputies with limited duties attend a 12-week, 162-hour academy; Level II reserve deputies with "full peace officer powers" attend a 15-week, 242-hour academy; and Level I reserve deputies, who are akin to full-time deputies, attend a 26-week, 451-hour academy that includes firearms training, according to the department.
How many hours of training are required varies, depending on the jurisdiction, but one thing is certain, Thompson said: Training volunteers is something sheriffs take seriously, with "very tough and rigorous standards."
How are the programs funded?
This may prompt the response, "Aren't they volunteers?" Yes, they are, but as the IACP points out, police departments still have to consider the costs of a coordinator, screening, training, work space, supplies, equipment and uniforms.
In a 2011 survey with 277 respondents, the IACP learned that 25% of programs were funded by federal grants, 16% by in-kind donations, 15% by a line item in an agency budget, 9% by community or corporate grants, 8% by monetary donations, 9% by other sources and 18% by a combination of sources.
Who can be a reserve police officer?
The Harris County, Texas, Sheriff's Reserve Command says it has 200 volunteers who come from all walks of life
, including engineers, mechanics, doctors, corporate managers, lawyers and ex-law enforcement and ex-military members.
This is pretty typical of reserve programs around the country, residents who keep their day jobs but chip in with their local police forces during their time off.
Bates, in fact, was an insurance executive.
Requirements vary, but departments tend to have a few things -- such as a minimum age of 21 and clean criminal record -- in common. In Harris County, you must have a Texas driver's license, good credit, either 30 hours of college credit or two years of military service, a clean physical exam, 20/20 vision naturally or corrected, normal hearing, no trace of illegal drug use and a psychological evaluation. You must also submit to a polygraph.
What sorts of jobs do they do?
In many jurisdictions, reserve deputies can do anything a full-time deputy does, after they complete training.
The Tulsa County Sheriff's Office says some of that that agency's 130 volunteers even work with the SWAT team. Reserve deputies have played a crucial role policing fairs, helping out after tornadoes and rescuing people from burning homes, Maj. Shannon Clark told CNN.
The Fulton County Sheriff's Office in Atlanta
says its reserves "work in every division of the Sheriff's Office and their duties include, but are not limited to civil service, warrants, courts, jail, crowd control, and charitable events."
Other departments limit their reserves to lighter duty, and the IACP report says some tasks doled out to reserves may assigned to duties such as chaplaincy, code enforcement, crime prevention, public outreach, translation, investigation, missing persons, patrol, equipment maintenance, schools, sex-offender management, traffic control, DUI checkpoints, victim services and warrant compliance.
"Every jurisdiction is different," Thompson said. "A very remote jurisdiction with very low crime, very low drug abuse, they probably need help for the Saturday rodeo. It just depends. Trying to apply a one-sized fits all approach is a mistaken undertaking."