Capt. Todd Jones of the Virginia Beach police, right, talks to Joe Whitesides, co-owner of an audio-visual company, about a GoPro camera that is mounted to his chest and streams video to a cellphone and nearby monitor. (Victoria St. Martin/The Washington Post)

If all goes according to plan, by next summer, Prince William County police officers will be wearing not only uniforms and bulletproof vests, but also body cameras.

Before officers don devices that could record each traffic stop or arrest, the department teamed with Fairfax County police to see exactly what’s out there.

“This is new technology. It’s evolving,” said Lt. Javid Elahi, the Prince William County Police Department’s information technology manager. “There’s a lot of pieces that go to this — it’s not just as simple as buying a camera and turning it on. You need to have policy, you need to have infrastructure, you need to have people to manage it.”

To put to rest questions such as how body cameras weigh and feel, the two departments hosted an expo in Chantilly last week with about 35 vendors. Organizers said hundreds of police departments from near and far registered, including those in the District and Montgomery County.

Sgt. Kim Chinn, a Prince William police spokeswoman, said the two-day expo was all about research.

“It’s new technology that we’re all going to have to get comfortable with, and I think there’s anxiety as well as the feeling that we may need this to protect ourselves, so there will be quite a learning curve,” Chinn said.

“It’s not like you go out and just buy a new car,” she added. “There’s so much that goes with it — all the backup, the storage, the retrieval, the managing, the randomly pulling tapes, pulling them for court, things like that. It’s a huge project.”

And it’s a project Prince William police said they are ready to tackle.

In April, county officials approved a $3 million plan to equip 500 of the department’s officers with the technology.

“My preference for body cameras is they go more places and see more interactions,” Police Chief Stephan Hudson said after the action.

Criminologists, police accountability advocates and officers say body cameras are beneficial because they provide a video record of interactions with the public. After last summer’s shooting of 18-year-old Michael Brown in Ferguson, Mo., police departments across the nation began examining their camera policies.

Prince William plans to kick off a pilot program with 35 cameras by next year, said Tom Pulaski, who oversees the department’s technical services division.

At the expo, Capt. Todd Jones of the Virginia Beach police examined the types of body cameras.

“We want to research thoroughly and make as educated a guess as we can,” said Jones, who added that his department has been examining the technology for three years. “Every time we answer one question, we uncover three or four or 10 more.”

Tod Burke, a criminal justice professor at Radford University and a former police officer in Ocean City and Howard County in Maryland, said that when it comes to the issue of body cameras, throwing money at the problem won’t solve it.

“That’s like throwing a Band-Aid on a hemorrhage,” he said. “You have to have policies in place with proper law enforcement training and, certainly, community education.”

Burke said policies should address sensitive situations, such as a domestic dispute — would the camera be on or off? Also, he noted, the technology raises concerns about witnesses and informants, and officer safety issues.

“You want to be able, as a police officer, to react to a situation,” Burke said. “You don’t want [them] to have to worry about, ‘Am I being recorded? Is something that I’m reporting going to be used against me?’ That type of thing. You don’t want them to hesitate.”

Burke said that cameras can’t prevent situations but that they can aid authorities, adding that early statistics show that departments with officers who wear body cameras have fewer incidents of police and citizen misconduct. And the video could help bolster eyewitness identification, said Burke, who usually conducts a class exercise that he says highlights the problems that arise when relying on witnesses alone.

He said he tells his class, “ ‘Okay, you’re a police officer, you’re giving a broadcast — be on the lookout for a white, black, Hispanic, transgender person, who is anywhere between 5-foot-5, 6-foot-3, 135 to 200 pounds,’ and they start laughing,” he said. “It’s not that [witnesses are] lying; this is really what they thought they saw.”

Burke said when it came to witnesses and Ferguson, there was a question of whether Brown had his hands up just before the shooting.

“Perception really does make a difference,” Burke said. He pointed to an investigation that later concluded that Brown’s hands probably were not raised. “The advantage of having a body camera at that time, that would have been answered.”