Last week, following the announcement that the New York grand jury had decided not to indict Daniel Pantaleo in the killing of Eric Garner, Eric Holder announced that the Department of Justice would be opening an investigation into the matter. And the Monday prior, after the no-indictment decision by the grand jury in Ferguson, the DOJ reassured us that the investigation into Darren Wilson that they had begun back in August immediately after Mike Brown’s death would continue.

We often greet such announcements with cheers and open arms. And indeed, a DOJ investigation may lead to much-needed structural reforms of the police departments under scrutiny. But for those of us who want justice for Eric Garner and Mike Brown specifically, the truth of the matter is that the DOJ doesn’t have a lot of options.

As mentioned previously by Jessica Mason Pieklo on Rewire, the DOJ could bring a lawsuit against the police officers under 18 U.S. Code section 242, a federal statute that authorizes the prosecution of police officers for violation of citizens’ constitutional rights. In addition to the problems Pieklo discussed that can arise from federal prosecutors coordinating with local police forces, the burden of proof for such cases is practically insurmountable: The prosecutor has to prove that the police officer willfully subjected a person to the deprivation of his or her constitutional rights.

In other words, a federal prosecutor would have to prove that not only did Darren Wilson and Daniel Pantaleo use excessive force against Mike Brown and Eric Garner respectively, but also that they intended to do so. And as you might imagine, it’s very difficult to prove intent at trial unless there is video evidence of an egregious violation of constitutional rights, as there was with the eventual successful federal prosecution of two of the four police officers who assaulted Rodney King.

But, you may be thinking, there’s video evidence in the Eric Garner case—isn’t that enough?

Maybe. The fact that Pantaleo used a banned technique to subdue Eric Garner—the choke hold that ultimately led to Garner’s death—certainly helps. But it’s likely that a federal grand jury wouldn’t find that constitutes sufficient probable cause to believe that Pantaleo willfully violated Garner’s constitutional rights. And it’s even more likely that a federal prosecutor would find it impossible to prove that Pantaleo intended to kill Garner. A federal jury would likely decide that Garner’s death was an accident. I think it’s safe to say that Pantaleo’s actions don’t rise to the same level of egregiousness as a police officer beating Rodney King into a pulp at the behest of his police sergeant.

The fact of the matter is that the DOJ is better at dealing with structural problems in a particular police department through “pattern or practice” cases than it is at prosecuting individual police officers for instances of excessive force or police brutality.

Pattern or practice cases are brought by the Department of Justice under the Violent Crime Control and Law Enforcement Act, which Congress passed in the wake of the Rodney King beating and the subsequent riots. The law authorizes the U.S. Attorney General to file lawsuits against entire police departments that have engaged in a “pattern or practice” of violating citizens’ civil rights in order to force them to reform.

For example, just last week, the DOJ released a “pattern or practice” report containing the results of its investigation into the Cleveland Police Department, which it began in March 2013. (That police department currently happens to be in hot water because one of its officers essentially executed 12-year-old Tamir Rice in what journalist Ta-Nehisi Coates aptly described as a “state-authorized drive-by.”)

As a result, Cleveland, under threat of being sued for civil rights violations by the DOJ, will be forced into a consent decree, which is a settlement agreement authorized by a federal judge, between the police department and the federal government. Based on the requirements of previous consent decrees, this will likely require Cleveland to implement reforms such as mandating cultural sensitivity training for police officers, creating new “use of force” policies, keeping automated records on the performance of police officers, enacting early warning systems to identify problem officers, increasing community outreach, and the like. Once the Attorney General is satisfied that Cleveland has complied with the terms of the consent decree, the federal judge overseeing the case will release Cleveland from its obligations under it.

Most consent decrees last for a period of five years, but some reform efforts can take a decade or more. For example, the consent decree imposed on the LAPD in 2001 in the wake of the Rampart Division Scandal was just lifted last year. And of course, if at some point in the future Cleveland regresses and there are more rights violations, then the federal government can open a new investigation and subject Cleveland to yet another consent decree. (The Pittsburgh Police Department, for example, is currently under investigation for corruption and may be subject to another consent decree barely a decade after the first consent decree was lifted.)

Since cop culture is generally resistant to change, these sorts of consent decrees are important tools that compel police departments to examine the way they have been operating and to reform their practices in order to better serve the communities they police. And, in a sense, they are more useful than the prosecutions of individual police officers, since consent decrees require structural and meaningful change in the ways that police departments operate. In turn, these sorts of reforms can reduce incidents of police misconduct and senseless brutality. While prosecutions of individual police officers may be satisfying, they can lead to complacency in police departments, which may be quick to dismiss an individual case as the rogue actions of one bad apple.

I don’t mean to suggest that the DOJ never prosecutes individual police officers. They do. The Rodney King trial is a shining example of that. But the Rodney King trial involved a group of police officers practically beating a man to death in a manner that could never be construed as “accidental” or “unintentional.” In general, however, the burden of proof in federal police misconduct cases is so high that winning such a case is nearly impossible—and it’s therefore unlikely a prosecutor would take it on.

Ultimately, it is unrealistic for us to expect the federal government to swoop in and provide justice in individual cases, especially when the tools that they have at their disposal are limited. I hate to be a downer, but we need to be realistic about the sort of justice we can expect from federal prosecutors after state prosecutors refuse to file charges or secure grand jury indictments.

The bottom line is this: It’s unlikely Wilson or Pantaleo will be prosecuted. It’s far more likely that the Ferguson and New York City Police Departments will be forced to reform.

And while that is cold comfort to the families of Mike Brown and Eric Garner, the sort of reform that results from consent decrees just might decrease tensions between the police and the communities they are supposed to serve.