What can Washington do about militarized police forces?

Washington lawmakers let out a collective gasp on Thursday after seeing startling images of police officers decked out with combat gear and tanks to respond to largely peaceful protesters in Ferguson, Missouri.

While there may have been some looters and violent individuals among the demonstrators who gathered to protest the killing of unarmed 18-year-old Michael Brown, the police looked more equipped to enter a war zone than a protest, liberal Sen. Elizabeth Warren, D-Mass., and conservative Sen. Rand Paul, R-Ky., agreed. Attorney General Eric Holder said in a statement, "At a time when we must seek to rebuild trust between law enforcement and the local community, I am deeply concerned that the deployment of military equipment and vehicles sends a conflicting message."

Although the images seemingly shocked members of Congress, the issue of police militarization was born in Washington and has been percolating for years. The images out of Ferguson may finally serve as a tipping point needed to prompt lawmakers to reform the policies that allow local police forces to acquire Defense Department equipment without having to say much about how it's used or where it ultimately ends up.

With billions in equipment already disbursed across the country, it may seem too late to put the genie back in the bottle. But public advocates pressing for change say there's plenty Washington can do to curb the disbursement of such equipment -- and even potentially take some of it off the streets.

"So much of the militarization of policing is fueled by federal programs, I think it's important for the federal government to take the lead here," ACLU criminal justice expert Kara Dansky told CBS News.

Already, Rep. Hank Johnson, D-Ga., has produced legislation that would put some constraints on the federal program that allows the Pentagon to give police forces equipment for free. Johnson's bill represents just one step Washington could take to address an issue that he's been warning about for months.

"Something potentially sinister is happening across America, and we should stop and take notice before it changes the character of our country forever," Johnson co-wrote in a USA Today op-ed in March. "County, city and small-town police departments across the country are now acquiring free military-grade weapons that could possibly be used against the very citizens and taxpayers that not only fund their departments but who the police are charged with protecting."

The congressman made note of the several towns, and even at least one college (Ohio State University), that have acquired Mine-Resistant, Ambush-Protected vehicles (or MRAPs) in just the last few months thanks to the Pentagon's 1033 program. The program was approved by Congress in the 1990s and has since given police forces more than $4.3 billion worth of property such as MRAPs, pistols, automatic rifles, and flashbang grenades.

"Why is there surplus, especially when the Defense Department is threatening to cut jobs anytime Congress talks about defense cuts as part of sequestration or the Budget Control Act?" Johnson asked in his op-ed. "The primary reason is that we're drawing down from two major equipment-laden wars in Iraq and Afghanistan, and while some of this equipment is being destroyed in the war zone, at a loss of billions in American taxpayer dollars, much of it is now being returned to the U.S."

On top of receiving equipment directly from the 1033 program, police forces can buy equipment like drones and MRAPs with terrorism grants from the Department of Homeland Security. The department has doled out $34 billion in grants since the program started after 9/11.

In addition to limiting transfers in the 1033 program, Johnson's bill would call for some accountability in the program.

"One of the big issues that inspired this legislation is some of the smaller equipment, the assault weapons, were unaccounted for, they were given away to friends," Michael Shank of the Friends Committee on National Legislation told CBS News. "Just the accountability of these free weapons going to police chiefs and police forces was really problematic."

At one point, the office that oversees the 1033 program suspended the transfer of firearms to police forces because there were so many problems, the Associated Press reported last year, such as former military firearms being sold on eBay. In New York last year, lawmakers thought the job of tracking equipment from the 1033 program could be handled by an unpaid intern.

Johnson's bill would prohibit the Defense Department from giving any more equipment to an agency that couldn't certify the whereabouts of prior equipment it received.

While Congress considers actions to reform the program, the administration could act on its own, Danksy said.

"The law that Congress passed in the 1990s... doesn't mandate DOD simply give the police whatever they want," she said. "The DOD could easily put some constraints on that, and we think they should do so."

Additionally, the Justice Department could use the power of the bully pulpit to urge police departments to retire or give back their equipment.

"Local police departments get a lot of money from DOJ, and that gives them an opportunity to encourage them to exercise restraint," she said.

Shank said that the Pentagon could go so far as to issue a recall of its equipment. "A recall on MRAPs, for example," he said. "Just like a car company would recall their cars."

So far, it doesn't seem like the Pentagon has any interest in curbing the program.

Navy Rear Adm. John Kirby, the Pentagon press secretary, said the 1033 program "serves a purpose."

"This is a useful program that allows for the reuse of military equipment that otherwise would be disposed of that can be used, again, by law enforcement agencies to serve their citizens," he told reporters Thursday. "That said, it is up to law enforcement agencies to speak to how and what they gain through this system."

While the Pentagon may not have any interest in changing the program, Shank said he's optimistic Congress will act.

"We're absolutely at a tipping point," he said. "Any (congressional) office we talk to about this is on board. They find it egregious, whether Republican or Democrat."

Shank said it's unclear to him why the issue may be gaining momentum now, unlike in previous years when egregious police force was on display -- for instance, during the World Trade Organization protests in Seattle in 1999 or the Occupy Wall Street protests in 2011. However, he suspects that politicians could be paying attention now because Michael Brown's killing underscores the way militarized policing disproportionately targets minority communities.

A report that Dansky helped produce for the ACLU last year, analyzing the use of Special Weapons And Tactics (SWAT) Teams in 2011 and 2012, found that the "use of paramilitary weapons and tactics primarily impacted people of color."

In a Time op-ed he wrote in response to the Ferguson events, Sen. Rand Paul addressed that very point.

"Anyone who thinks that race does not skew the application of criminal justice in this country is just not paying close enough attention," he wrote.