There’s at least one thing the family of Michael Brown and law-enforcement officials have in common: they both support body cameras for police officers.

Protesters and police alike are rallying around the devices, which supporters say will reduce the uncertainty surrounding police encounters.

But even as legislation requiring their use remains to be seen, and some experts question their efficacy, body cameras are already raking in record sales for manufacturers—and are poised to bring in even more cash in the months ahead.

At a rally in Chicago this week, President Obama asked Congress to authorize $75 million in federal spending over the next three years to help police departments purchase up to 50,000 body cameras.

And since August, more than a dozen law enforcement agencies have announced their plans to test and buy the cameras, including large police departments like New York, Chicago, Los Angeles and Miami-Dade County.

In September, Miami-Dade officials approved $1 million to purchase 500 cameras. This means that almost half of the police officers in Miami Dade County will be recording their interactions with citizens next year.

“If there is an incident, we will know exactly what happened. So, we won’t have to go through what happened in Miami in the 1980s or what happened in Ferguson,” Miami-Dade Mayor Carlos Gimenez told Fusion.

“It will be a huge mistake for us to not get them,” he said.

With both the police and the public on board, according to opinion polls and a recent Justice Department report, shares and sales of the biggest body-camera manufacturers have surged since last summer.

Taser International, the pioneer of stun guns and a leading maker of body cameras, says it has seen record sales this year. Profits from the cameras and supporting software skyrocketed from about $1 million to $2 million in early 2013 to nearly $11.4 million in the last quarter.

RELATED: More than 1,200 police departments are equipped with body cams

Just to put that in perspective, since 2012 the company has sold cameras to 1,200 agencies in the U.S.—and 80 percent of those sales occurred in the last 12 months.

Steve Tuttle, Taser’s spokesperson, told Fusion that Ferguson changed his life.

“It not only changed the sales factor, it changed the awareness factor,” he said.

Tuttle said interest has changed drastically over the last year. “People came back to us,” he said. “These are guys who did not only say no, but they said ‘Hell No!’ a couple years ago.”

Tuttle has been attending at least one police event and department monthly and has done about 125 media interviews to promote the cameras.

“When you ask officers about Ferguson, they say, ‘That could be our department.’ When you ask police officers, they say ‘That could be me.’ When you ask the public, they say, ‘That could be our city,” Tuttle told Fusion.

In October, when Fusion attended the International Association of Police Chiefs annual conference—known as the “Super Bowl” for police officers—body cameras booths were some of the busiest spots.

Here is one picture we took at the Taser International extravagant booth.

Police officials make long lines to watch a Taser International body-camera presentation at a conference in October.

Vievu was one of the largest companies showcasing the technology. More than 4,000 agencies carry its cameras in 16 countries.

“This year has been phenomenal,” Steve Ward, Vievu’s CEO said.

Ward did not reveal specifics on sales, but he told us that requests to test the cameras have been up to 70 percent since September.

“Quite frankly, we had a record revenue,” he said.

Nearly 2,000 watched Taser International presentation on body cameras at the IACP annual police conference.

New technologies tend to benefit from tragedies like Michael Brown.

It was the brutal beating of Rodney King that pushed police departments to use “less-than lethal weapons” like Tasers and get dash cameras in their cars.

Taser International shares has been up 2.84% following the Ferguson grand jury’s announcement and the company’s deal with Winston-Salem police department. The Arizona based company has experienced continuous growth this year but Taser wants more.

“The policy when you become an officer will be you get a gun, a Taser, a badge and a camera,” Taser International CEO Rick Smith, predicted to Forbes.

He said he hopes that the camera is made by Taser.

Dan Lieberman contributed reporting.