This Chart of U.S. Vets' Postwar Killings Doesn't Tell the Whole Story

Yesterday, Huffington Post published this infographic depicting "The Deadly Aftermath Of War Right Here At Home." It got hot on Digg's front page. It might give you the impression that war veterans are killing Americans out of all proportion to the rest of the population. You'd be wrong.

The chart and accompanying article use last week's fatal shooting at Ft. Hood as a jumping-off point for a conversation about how America's long, dumb wars have deranged their veterans, leading to a rash of murders by them here in the states. It's a conversation worth having, to be sure: Ivan Lopez, the presumed Ft. Hood killer and an Iraq vet, was being treated for mental health issues, and may have suffered from post-traumatic stress.

But conversations need context, and that's sorely lacking in HuffPo's treatment—to a point where readers could be misled.

There are niggling details that the chart gets wrong—they're military installations, not installments—but that's neither here nor there. More concerning is the overall charge that the victims of vets here in America are "collateral casualties of war." Does the evidence really bear that out?

HuffPo counts a total of 194 war vets who've been charged with criminal killings post-deployment. It's not clear when the tally stopped, but that's a good sight more deaths than were recorded by GOOD magazine in 2010, so let's assume HuffPo's numbers run up to at least last year, when the recorded number of Iraq and Afghanistan veterans totaled about 2.5 million.

That's a hell of a number, by the way. It amounts to less than 1 percent of Americans, sure, but still, a city of nothing but "War on Terror" veterans would be the fourth largest city in the U.S., just behind Chicago.

But would it be an especially lawless, stabby, shooty city? Do the math: Of those 2.5 million vets, 194 have been accused of murder or manslaughter here in the States. So 0.0078 percent of returning vets are accused killers.

It would be nice if we could compare that to the percentage of Americans at large who are accused of killing, but those stats are hard to come by; the FBI doesn't publish the number of murderers each year, in part because many don't get caught. We do know how many Americans are victims of murder or negligent manslaughter in a given year, though: 14,827 in 2012, for example. Say we assume one murderer commits one killing—it's an inexact (and macabre) estimation, but it gives us a reasonable ballpark figure to work with.

In 2012, there were approximately 314 million people in America. Assuming 14,827 murderers, that means 0.0047 percent of Americans were killers.

By that admittedly rough measure, war vets are about twice as likely as members of the general population to be killers. But that doesn't tell the whole story, either: There are plenty of variables that make a group more likely to kill.

A recent Department of Justice study, for example, shows that men are nine times more likely than women to be murderers. Since the military—and, by extension, the population of U.S. war veterans—is about 86 percent male, while the U.S population is only 49 percent male, you might expect the percentage of vets who are killers to be about twice the rate for all Americans. Which it is.

So it isn't totally clear that killings by vets are an alarming trend, so much as a disturbing pattern that's reasonably within historical expectations.

There is another interesting area of the infographic: the chart at the lower left that shows killings by vets track pretty closely with casualties in the wars (except for 2009, when the Great Recession pushed all crime rates up). The chart seems to intimate that the likelier troops were to see comrades killed overseas, the likelier they were to experience combat stress and kill at home.

That's intuitive. But that's not the way it works. At the Iraq war's bloodiest points, deployments were 12 months or more for most soldiers, and 7 months or more for members of the other services. They can't kill American civilians when they're deployed overseas, but they can after they get home. So if HuffPo truly is suggesting a link between war casualties and vets' killings at home, that latter group should be a trailing indicator on the chart. It's not.

More likely, higher casualties in war meant more troops choosing to get out of the service, lest they might deploy again... and consequently more war vets in the general U.S. population, and a statistically expected rise in their numbers of accused killings as a result.

Beyond the stats, the HuffPo piece offers no real evidence linking veterans' service overseas to the killing they do here at home. It's absurd to say there's no link, but it's equally absurd to say one experience causes the other. Plenty of other variables exist—debt, poverty, disability, drug dependency, relationship trouble, behavior control issues—although even with these, it's impossible to say whether a war deployment caused or aggravated the issues.

And inconvenient facts are absent from the HuffPo piece. The first Fort Hood killer, Nidal Hasan, had never deployed to a war zone—in fact, he was slated to go to Afghanistan, and he says that prospect, and the fear that he might have to kill fellow Muslims, precipitated his murderous act. He is responsible for 16 deaths. You could even argue his killing was caused by the wars, even more directly than some of the killings included on this chart. But he doesn't even appear on it.

The whole affair is less a telling snapshot about the after-effects of America's long, dumb wars than a clear-cut example of the limits of context-free charty "explainer journalism", which makes people feel more informed even when it perpetuates innumeracy and reductive myths.

All of this is not to say that war doesn't suck on every level, and that war veterans' difficulties don't pose a huge challenge for us as a society. But they're a huge, diverse population, and they get jammed into a couple of archetypes for media purposes: heroes, or victims, or monsters. Many are none of these. Some are all three. However you categorize them, vets could use some help today, as could a whole lot of other Americans.