That false “Marketplace” story about the former U.S. Army sniper credited with 17 kills who’d witnessed a murder outside of a Rite-Aid and played minor-league baseball and participated in Occupy Oakland? It was too good to check.

So how’d it happen? A representative for the San Francisco radio station that originated the story for “Marketplace” has a reasonable explanation.

“Things slip through,” says Scott Walton, executive director of communications at KQED.

But here’s Walton’s point — they don’t often slip through at KQED. The station has been running its “Perspectives” series — first-person stories such as the one from alleged sniper Leo Webb— for 13 years. And in each of those years, says Walton, “Perspectives” produces more than 250 segments. Never before has the station stumbled quite the way it did here.

It’s unclear whether that stellar record arises from the general honesty of people who tell their stories to public radio stations in northern California or from a meticulous fact-checking operation at KQED that just happened to falter with Leo Webb. Walton said he’d get back to me on how the station routinely checks out the testimonials.

KQED “has a mission to reflect the life of the Bay Area,” says Walton, and that mission requires getting non-run-of-the-mill voices onto the air. Those voices, from here on out, may be getting a touch more vetting.

One other thing: Walton says that Leo Webb was brought to the station’s attention by a partner organization, one to which this blog’ll be reaching out shortly. Also, the station has attempted to track down this great sniper-cum-baseball player in light of the embarrassment. “We have been unsuccessful in finding him,” says Walton.

Leo Webb had better do a good job of hiding, because the folks at ”Marketplace” are looking for him too. “We are doing a full review and vetting of the entire thing,” says Deborah Clark, the American Public Media executive producer of “Marketplace.” Though the “Marketplace” folks have attempted to find Leo Webb, no luck so far, says Clark.

The unfortunate episode, says Clark, came about because “we had a process and didn’t follow it.” That process includes verying identity and the basic facts of a story. It’s rare that “Marketplace” uses material from third parties, says Clark, who nonetheless takes “full responsibility” for the mistake.