President Obama on Monday announced that he will send Attorney General Eric Holder to Ferguson, Missouri. America’s top law enforcement official will meet with FBI agents conducting the civil rights investigation into the death of Michael Brown, the unarmed, black 18-year-old who was shot and killed by a white police officer a little more than a week ago. The investigation into Brown’s death—which will include a federal autopsy of his body—is expected to take some time. But its end will likely only mark the beginning of a larger probe into the Ferguson Police Department, which has seemingly gone out of its way to stoke protesters’ anger by refusing to clarify the circumstances of the shooting, and by greeting the originally peaceful protests with military-grade riot gear.

Any meaningful reconciliation to the chaos and conflict provoked by this episode will have to include reform of the Ferguson Police Department. But how could that be done? How do you fix a police department that has proven it can’t police itself?

If Holder concludes that there has been a pattern of misconduct by the police—either in the lead-up to Brown’s death or in its aftermath—the president has the ability to force widespread reforms within the department with the help of a law passed in the wake of the Rodney King beating. The provision in question, part of what was officially known as the Violent Crime Control and Law Enforcement Act of 1994, is “one of the most significant” pieces of civil rights legislation passed in the latter part of the 20th century, and also one of the most “overlooked,” according to Joe Domanick, the associate director of the John Jay College of Criminal Justice’s Center on Media, Crime, and Justice. The law gives the federal government two options: It can either formally pursue a federal civil rights lawsuit against the Ferguson Police Department by alleging a “pattern and practice” of misconduct or the administration and city officials can enter into what is known as a “consent decree” that would mandate a specific set of reforms that would then be overseen by an independent court-appointed monitor. Faced with the possibility of a costly court battle, most cities have historically taken the path of least resistance and signed on the decree’s dotted lines. Ferguson officials probably wouldn’t buck that trend.

According to Samuel Walker, the emeritus professor of criminal justice at the University of Nebraska at Omaha, such an outcome is “the best hope we have” for turning around the troubled department. The reforms that normally accompany a consent decree “really get at the critical issue here, which is the culture of the department,” Walker says. “Day in and day out, what do officers know they have to do and what do they know that they can get away with?”

For evidence of what happens when a department has a culture where officers have no reason to believe there is serious oversight, Walker didn’t need to dive far into the Ferguson timeline for Exhibit A—a video clip recorded this past weekend that captured a police officer shouting, “Bring it, all you fucking animals! Bring it!” at protesters. “If they know they can get away with that type of language, that really defines the culture of the department,” Walker says. “You need to change the way that [officers] think and act so they know they can’t do policing the way they are used to doing it.”

So what would such a consent decree actually look like in Ferguson? Each settlement is unique, but generally speaking they last a minimum of five years and ensure that the reform process is a public one. The agreed upon reforms have historically covered three main areas, according to Walker: overhauling of the department’s use-of-force policies, including how such incidents are investigated internally; enacting an early intervention system that relies on a variety of data, ranging from citizen complaints against an officer to the demographics of his or her traffic stops; and creating a clear, open process through which citizens can lodge complaints when they feel they’ve been mistreated. All three seem necessary in the wake of what we’ve learned about Ferguson in the past week.

In the past two decades, more than 20 cities have entered into such agreements with the federal government, both in big cities like Los Angeles and New Orleans and in smaller ones closer in size to Ferguson, places like East Haven, Connecticut, and Steubenville, Ohio. The results are mixed.

Reforms are often slowed when local officials fail to buy in fully to the need for change and resist. New Orleans Mayor Mitch Landrieu, for example, unsuccessfully tried to appeal a pair of decrees covering Orleans Parish Prison and his city’s police department, arguing the city didn’t have the money it would take to pay for the reforms. And as Domanick recounted earlier this summer, police in Cincinnati were so uncooperative during the time they were undergoing reforms that on “at least one occasion the monitor was actually kicked out of police headquarters.”

Still, there is evidence that real reform is possible, even if it takes time. The best-documented example of such an effort succeeding is, somewhat remarkably, in Los Angeles, where the beating of King by police helped prompt passage of the federal law in the first place. The city signed its consent decree in 2000 following a particularly shameful stretch that included both the King beating and the Rampart scandal that saw scores of officers affiliated with the department’s anti-gang efforts implicated in a variety of misconduct. Before the decade came to a close, however, there were already signs of significant improvement. An independent study published in 2009 by a trio of researchers at Harvard’s Kennedy School of Government found rather stunning results. “Policing in Los Angeles today is noticeably different from what it was only a few years ago,” the authors wrote then. “The quality of service to residents is higher, the perception of the LAPD as fair has risen, and the use of force is down.”

The numbers behind that conclusion tell an even stronger story, most notably this one: 83 percent of residents said that the police department was doing a good or excellent job. That, again, was less than two decades after residents watched in horror as news stations broadcast a home video of a group of LAPD officers beating an unarmed King nearly to death.

Still, the LAPD reforms did not happen overnight and the reform of the Ferguson Police Department, if it ever happens, would likewise take years. And even if that were to happen there is no guarantee that any changes that are enacted will become permanent. “Once the monitor goes away, will these reforms have been institutionalized? Can [police departments] sustain these reforms?” says Walker of the problems facing any reformed department, not just a hypothetical Ferguson. “We need to make sure that these things last.”