A year and a half after massive protests in Ferguson, Missouri, reacting to the 2014 police shooting of Michael Brown, Ferguson on Tuesday approved an agreement with the federal government to reform the city's police department and court system.

The agreement comes after Brown's death led to massive protests in Ferguson, helping give rise to the Black Lives Matter movement and its protests against racial disparities in the criminal justice system and police use of force.

Justice Department and Ferguson negotiators tentatively agreed to policing reforms in January. But the agreement stalled last month, as the Ferguson City Council raised concerns about costs. But the Justice Department threatened a lawsuit, and told Ferguson officials that their cost concerns were inflated, pushing city officials to finally accept the agreement.

The reported agreement, known as a "consent decree," is very broad. It requires that the city equip all officers who are "reasonably expected to regularly interact with the public" with body cameras within 180 days. It tasks the Ferguson Police Department with reorienting its use-of-force policies to emphasize deescalation and avoid force. It forces the city to overhaul its municipal court system. It mandates a community-oriented approach to policing.

Most importantly, it requires an independent monitor to oversee implementation of these reforms and many others — as is standard with the federal interventions into local police departments. (Read the full consent decree here.)

The lawsuit and proposed agreement followed a Justice Department investigation that found enormous problems: Federal investigators uncovered a pattern of racial bias in the Ferguson Police Department, arguing that the disparities could only be explained, at least in part, by unlawful bias and stereotypes against African Americans.

Federal investigators uncovered a pattern of racial bias in the Ferguson Police Department

The disparities were also rooted in the city's reliance on the police department and courts for local budget revenue: Federal officials found that city officials worked together at every level of enforcement — from city management to the local prosecutor to the police department — to make as much money from fines and court fees as possible, ranging from schemes to raise total fines for municipal code violations to asking cops to write as many citations as possible.

As a result, Ferguson residents — particularly black residents — were overpoliced.

But will the consent decree solve these issues? The history of similar federal interventions suggests they have a mixed record, so there's a good chance of failure and, at the very least, struggles along the way.

But even with murky prospects, the consent decree certainly stands as a prominent symbol of America's shift on race and policing.

Federally enforced police reform agreements have a mixed record

Do federal interventions into local police departments work? The Justice Department certainly seems to hope they do — under President Barack Obama, the federal agency has undertaken more such investigations than the administration's predecessors.

But the Justice Department hasn't studied the long-term impact of these types of interventions, leaving it to reporters and researchers to figure all of this out.

In an exhaustive investigation, Frontline and the Washington Post looked into whether federal interventions into local police departments work. The results were mixed:

The reforms have led to modernized policies, new equipment and better training, police chiefs, city leaders, activists and Justice officials agree. But measured by incidents of use of force, one of Justice’s primary metrics, the outcomes are mixed. In five of the 10 police departments for which sufficient data was provided, use of force by officers increased during and after the agreements. In five others, it stayed the same or declined. None of the departments completed reforms by the targeted dates, the review found. In most, the interventions have dragged years beyond original projections, driving up costs. In 13 of the police departments for which budget data was available, costs are expected to surpass $600 million, expenses largely passed on to local taxpayers. Officer morale in some of the departments plummeted during the interventions, according to interviews. Collectively, the departments have cycled through 52 police chiefs as the agencies tried to meet federal demands. Some departments have struggled to sustain reforms once oversight ended, and in some cities, police relations with residents remain strained.

The biggest barrier to the implementation of these reforms is the cost. Generally, the Justice Department's interventions force local governments to shell out millions of taxpayer dollars to alter their police departments.

Los Angeles, for instance, told Frontline and the Washington Post that its reforms — which were part of the costliest and longest reform effort by the Justice Department to date — added up to about $300 million over 12 years after 2000.

But Los Angeles is lucky in that it could actually afford the reforms. Other places fared much worse: Puerto Rico, for example, estimates that it will cost $200 million over 10 years to reform its police after a Justice Department investigation that began in 2008 — but the island is currently more than $70 billion in debt.

The costs could be a big problem for Ferguson. Remember: The reason the city must reform its policing practices in the first place, according to the Justice Department, is that it used its police and courts as a revenue-generating operation — a sign of how desperate the city was for funds.

Now Ferguson is being told not only to abandon revenue-focused policing (the right call, policing experts say), but also to shell out potentially tens of millions of dollars to change its police and courts. That's one of the reasons the Ferguson City Council was concerned about costs — but it looks like the city will have to pay up anyway.

The Ferguson agreement has tremendous symbolic importance

Although the consent decree's full effects remain unclear, it's hard to deny that the agreement has already had a symbolic effect on the city and perhaps the country.

When former police officer Darren Wilson shot and killed Michael Brown, much of the media attention focused on shooting specifically. To this day, what exactly led up to the shooting remains unclear. (The Justice Department, for one, found evidence that Brown had attacked Wilson, and concluded that there wasn't sufficient credible proof to disprove Wilson's claim that he felt reasonably threatened when he shot Brown.)

But the protests over Brown's death were always much bigger than one shooting. In Ferguson, local residents were protesting the city's revenue-focused policing and how it disproportionately targeted and hurt black people — concerns that were validated by the Justice Department's investigation later on.

On a broader scale, demonstrators were also protesting vast racial disparities in the criminal justice system and police use of force that extend to the entire nation.

To see the protests not just be validated by the Justice Department investigation but also lead to significant change in the Ferguson Police Department is hugely important. It shows one of the very tangible effects the Black Lives Matter movement is already having in the US.

After all, if people hadn't taken to the streets of Ferguson, would there be any change today? Considering race and policing issues barely got any mainstream media coverage only a few years ago, that seems very unlikely. (Polls also show Americans were less likely to view racism and black people's treatment in the US as big issues prior to the events in Ferguson in 2014.)

Again, the consent decree's effects remain unclear — and probably won't be known for years to come. But the fact that serious reform is even possible in a small Missouri town that almost no one knew about two years ago says a lot about how government officials now see concerns over racial disparities in the justice system.