When is the right time to have a debate on public policy after a deadly tragedy? Immediately, later, or never? It often seems to depend on which side believes they can score political points or lose them, and the impulse to speak out usually outstrips the data-gathering process, with embarrassing and long-lasting consequences.

In the case of the shooting in Aurora, Colo., that left 12 dead on Friday, we saw yet another example of this — and not from bloggers, or from Twitter, but instead from the supposedly responsible media. When the name of the alleged shooter became known, ABC News' Brian Ross went on the air with what he thought was a scoop: A man with the same name from the same town had been an activist in the local Tea Party, Ross said on the air. "Now, we don't know if this is the same Jim Holmes," he said, "but it's Jim Holmes of Aurora, Colorado."

As it happens, a Jim Holmes of Aurora, Colo., had participated in Tea Party rallies... but not the Jim Holmes who allegedly murdered 12 and wounded dozens of others in the movie theater. The Jim Holmes who Ross mentioned was presumably just as horrified by the crime as the other thirty-plus James Holmeses in the Aurora and Denver area. To make matters even worse for ABC, Ross hadn't even contacted the Tea Party activist before he went on air, prompting the wrongly implicated Holmes, a middle-aged, former law enforcement officer, to ask The Daily Caller two rather pertinent questions:

"What kind of idiot makes that kind of statement?" Holmes told The Daily Caller. "Really, seriously, how do we take a journalist seriously when it's pretty clear they really haven't done any sort of check on their facts?"

It's not the first time that national media has seized the opportunity to implicate the Tea Party in the wake of a shooting. After former Rep. Gabrielle Giffords was shot in Tucson, Ariz., last year, and six people were left dead, the media jumped to the conclusion that the alleged shooter was motivated by political animosity toward the Democrat. Commentators also rushed to blame Sarah Palin, who, in political action committee mailings, used crosshairs to illustrate which House districts — including Giffords' — she was "targeting." Oddly, no one mentioned that politicians and political groups in both parties have often used bullseyes and crosshair symbols for the exact same purpose without being blamed for inciting a killing spree. Eventually, we learned that the accused perpetrator Jared Loughner not only had no connection to the Tea Party, but apparently none to reality, either.

Americans have repeatedly rejected an expansion of gun control because it doesn't work.

At least in the Arizona case, the shooting of a member of Congress might excuse the impulse to blame extreme politics. The Aurora massacre provides no such excuse. The shooting took place at a midnight showing of the new Dark Knight movie, with no political figures in attendance. Despite the fact that the massacre had just taken place a few hours earlier, and the only detail ABC had was a name, Ross' first apparent instinct was to look for a Tea Party connection.

Small wonder, then, that conservatives have balked at conducting a debate on gun control in the midst of such irresponsible behavior by the media. Though, in actuality, the main reason so few are interested in the debate is because it has largely been fought and decided. Americans have repeatedly rejected an expansion of gun control because it doesn't work. Look no further than Aurora, where both the city and the theater where the shooting occurred have rules forbidding the carrying of any firearms (the city statute was deemed unenforceable, however, because of the state's concealed-carry permit statute). On top of that, no one can fire a weapon within Aurora city limits except at gun ranges — not even, apparently, in self-defense. Of course none of that stopped the perpetrator in this case from committing the murders.

What about other areas where gun-control legislation has been implemented? Illinois has the most restrictive carry laws in the country, and Chicago has one of the toughest gun-control regulations among cities. Yet the murder rate for Illinois is above the national average, according to the FBI (5.5 per 100,000 in 2010, compared with 4.8 murders for the rest of the country), as is the state's violent crime rate (435.2 incidents per 100,000 compared with 403.6 nationally). Chicago recently lost a gun-control case at the Supreme Court (McDonald v. Chicago), but the city lost the gun-control argument years ago — considering that its murder rate is 18th among large American cities, at 15.2 per 100,000, more than three times the national average. Washington D.C., which in 2008 lost its own Supreme Court gun-control case, ranked seventh in 2010 with a 21.9 rate. For the record, Aurora's murder rate was 7.1 per 100,000 in 2010, while other Colorado cities were significantly lower: 5.0 for Colorado Springs and 3.6 for Denver.

In comparison, Minnesota a few years ago passed a must-issue law that requires counties to issue carry permits unless specific reasons exist to deny the application. Critics of the law insisted that it would lead to a wave of shootings. Instead, in Minneapolis, crime rates have fallen to 1980s levels, with a murder rate of 9.7, 30th for large American cities despite Minneapolis' being 16th in size. Its twin city St. Paul has a murder rate of 5.7. Other factors certainly contributed to those decreases in violent crime, but clearly, allowing responsible and law-abiding citizens to own and carry firearms did not increase crime rates.

All this goes to show that when it appears that laws or policies have failed, as tragedy sometimes reveals, it's our duty to open a debate about how to improve or change our laws to prevent such incidents in the future. That debate shouldn't be based on anecdotes, and it shouldn't ignore actual evidence in favor of emotions that arise in the immediate aftermath of singular events. We owe more to the victims of these tragedies, and to those who have to live with the public policy we create.