Don't be surprised if you spot Snellville retiree Kathy Gestar in a patrol car.

The former Coca-Cola administrative assistant isn't in trouble, and she hasn't decided to join the force, but she is part of this year's Citizens Police Academy. She and a handful of others are getting an up-close look at what police regularly encounter.

Kimberly Smith/AJC (ENLARGE)

Snellville Police Chief Roy Whitehead talks about some cases his department has investigated during a Citizens Police Academy class.

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"You always think they're going to be rough and gruff, but they're just professional," Gestar said of the several officers and detectives she has met through the program.

Snellville Police Chief Roy Whitehead also pops by at times to share some of his own on-duty experiences, ranging from funny to frantic.

The program, in its sixth year, covers everything from DUI roadblocks, drug seizures and search warrants to robbery and homicide investigations.

"It's fun," Gestar said of the interactive lessons. "They don't hold back."

Classes are typically held on Tuesday nights and run for 10 weeks.

During an upcoming Saturday class, program participants will get to shoot firearms. They have already climbed behind the wheel of a patrol car and flipped on the blue lights and sirens.

"It's an opportunity for the citizens in our community to interact with police officers in a positive setting and to understand the things that we face on a daily basis," the chief said.

One of the instructors, Det. Dean Boone, said he enjoys the rapport with residents.

"A lot of people don't realize how hard and stressful our jobs are," he said. "We are regular, caring human beings."

During a recent Tuesday session, Boone and Det. Sgt. Ray Gunter explained the dozens of steps involved in investigating a robbery or murder.

Gunter described the importance of securing a crime scene with yellow tape that reads: "POLICE LINE — DO NOT CROSS." The barrier blocks residents from walking into the crime scene and contaminating the evidence.

Participants said they'd seen that on TV crime shows but didn't know if that's how real police rope off an area.

The detectives discussed fingerprinting and DNA collection and analysis, pointing out that it's not as easy as it looks on popular shows like "CSI."

"Unlike 'CSI', we don't get it back that day," Boone said. "It takes months, and sometimes it's inconclusive."

Enough residents have been misled that some prosecutors now take time during jury trials to explain how reality differs from TV fiction. In what is now commonly called "the 'CSI' effect," residents might expect detectives to always find fingerprints, DNA matches and the murder weapon.

In actuality, detectives told their citizens class, sometimes criminals wipe away evidence, wear gloves, dispose of murder weapons and don't leave a large enough amount of DNA to be a workable sample.

Class participant Doug Henry, a Norcross businessman who is taking the class with his wife, Ginger, said he learned to be more aware of his surroundings because you never know who will turn out to be a criminal or where they'll strike.

"We aren't in the same bubble we were in before," he said.