If the Alameda County Sheriff's Office has its way, surveillance drones may soon fly overhead.

But the potential use of drones is raising concerns about privacy and the possibility that local police departments are becoming too reliant on military tools to fight crime.

Since announcing its plan to evaluate the use of drones, the sheriff's office said that drones are a potential tool that can be effective in fighting crime.

"We believe that (drones) can be a great help in a number of specialized situations including tracking down fleeing suspects," Sgt. J.D. Nelson of the Alameda County Sheriff's Office said. He added that the agency has been studying the potential purchase of a drone for a few months and recently tested a model.

"It fits in a trunk," he said. "It can be folded up and then deployed when we need it."

He said that the sheriff’s office was looking to spend about $50,000 for the surveillance item.

"But there are some that cost around $500 or less," Nelson said, adding a purchase of a surveillance drone would be less costly than other aerial tools like a helicopter. "It's significantly more expensive to own and operate."

Concerned First Amendment groups say the use of drones is another sign that law enforcement agencies are turning towards quasi-military tactics for addressing crime. Linda Lye, staff attorney with the Northern California ACLU, said that in recent years, law enforcement agencies have stocked up with equipment that originated with the military.

"Part of what's going on is that since 9/11 we've seen a wave of military hardware flooding local police departments because of federal grant money from Homeland Security," she said." The acquisition of technology shouldn't be driven by outside money."

Nelson said that it's natural for law enforcement agencies to expand their crime fighting tools.

"We don't use pagers anymore," he said. "We've updated our technology."

Nelson said that law enforcement has been incorporating military-style procedures and tool for many years.

"The reality is we use technology from the military and they use items developed by law enforcement," he said. "Handguns were a military development; before that we were using revolvers. We started using robots in certain situations not because they originated with the military, but because its top-of-the-line technology."

The ACLU of Northern California has filed a public records request with the sheriff's office asking why the drone is needed and how it will be used.

"The purchase of drones should be transparent with open discussion on the benefits and hazards of these items," Lye said.

Nelson said that those concerned about drones are overreacting.

"If they were a kidnapping victim or if someone was barricaded somewhere with a gun, then they wouldn't have a problem with us using this tool," Nelson said.

Isaac Ontiveros of the grassroots group Critical Resistance said that Oakland could be a fat target for drone surveillance.

"There's already a lot of surveillance of citizens in Oakland," Ontiveros said. "A gang injunction very much relies on surveillance of people and their actions. Paroled individuals often have to wear GPS tracking ... and we have a large population of parolees."

As the county's largest city, Oakland makes up more than half of conviction by the Alameda County District Attorney's Office, with many of those cases originating from arrests by the sheriff's office.

It's unclear when the county sheriff will make a final decision, but the agency seems to be leaning towards the purchase of a drone. Last weekend, the agency tested a drone at a tactical event for county law enforcement and EMS workers called Urban Shield. Along with the law enforcement groups in attendance, there were dozens of vendors hawking their high-tech items to policing agencies.