In a piece I wrote yesterday about the killing of Trayvon Martin, I urged America not to turn its back on the government and put the law in private hands. Martin’s killer, George Zimmerman, is an example of how vigilante justice can (and does) go so wrong.

But many who responded felt that my solution—reforming the police force, rather than abandoning it—didn’t give enough airtime to the history of police brutality in this country. And it’s an important and disturbing one. The violence used to crack down on Occupy Wall Street just this past weekend is a perfect example. But violence against Occupy has been a visible incarnation of a problem that black America has long lived with. Elon James wrote eloquently about this when Occupy was first under attack: “While the Occupiers were dealing with such abuse, during civil disobedience, communities of color suffer these type of injustices simply because it’s Wednesday.… Abuse of this kind is all too familiar to the black community. If someone hasn’t directly experienced it, they probably know someone who has.” The NYPD, which has been at the forefront of using violence against Occupiers, is also at the forefront of racially repugnant policies. Its stop-and-frisk policy hit another record last year with 684,330 stops, and blacks and Hispanics were 87 percent of those stopped—whites were just 9 percent. Its violent tactics against minority groups led to the deaths of Sean Bell and Jateik Reed—both unarmed—and countless others.

While these actions make me sick, they only strengthen my resolve to reform our country’s police force. Because my question still remains: What’s the alternative? It absolutely cannot be putting the law in the hands of private citizens like George Zimmerman and Joe Horn, the Texas man who shot two men on his neighbor’s lawn.

“Stand your ground” laws are not an answer. Beyond encouraging vigilantes, they have coincided with a rise in “justifiable homicides.” Florida’s law was enacted in 2005; since 2007 those incidents have doubled. The laws embolden citizens to shoot first and ask later, in large part because they’re no longer required to retreat or try to resolve the conflict before using force. They have also extended the realm of self-defense from someone’s home to the public sphere, and they’ve been used to defend the use of force to protect property, not just personal safety.

That was the case with Joe Horn. Josh Barro pointed out that my first piece didn’t include the fact that the two men he shot were apparently in the midst of a robbery. But Horn’s decision to ignore the orders of the 911 operator and leave his house to take matters into his own hands—which meant shooting both men, killing them then and there—was just as repulsive whether these men had been robbing his neighbor or just standing around. Stealing property doesn’t warrant death. Horn’s actions were just plain wrong.

As I said yesterday, we can put men like Horn and Zimmerman in jail for these crimes (although Texas’s Castle Law got Horn off the hook). But that doesn’t do enough to correct and prevent these injustices. Radley Balko pointed out that police don’t protect us, but respond to crime as it is happening. Will private citizens protect us, Batman-style? As I said before, there is an opportunity for reform if the police aren’t adequately protecting citizens. We can’t do the same to individuals.

The police force—with its ugly history of racism, sexism, and violence—can be made better. That has to be our goal. Because policing citizens is only a job for the government. The alternative, embodied by Zimmerman and Horn, will mean justice for very few.