Ed mentioned it already in the Greenroom but I want to chip in a post of my own to emphasize how commonplace this is now when mass killings occur. Big media’s not always the chief culprit — the theories about Sunil Tripathi being one of the Boston bombers began online, as far as I know, not among the big boys at the networks — but given how much pride they take in having higher standards than the Internet hoi polloi, they’re the culprit more often than you’d think.

By my count, this makes three times in slightly more than a year where someone in professional media has misidentified a killer publicly. Ben Howe reminded me that Brian Ross didn’t pull his infamous theory about tea partiers after the Aurora shooting out of thin air; he googled for James Holmeses in Colorado and that led him to a tea-party site listing a “Jim Holmes” from Aurora as a member. In the hours after Newtown, CNN reported that it was Ryan Lanza, not his brother Adam, that was the gunman at Sandy Hook Elementary, a mistake that blew up so quickly that Lanza had to pause during his family’s implosion to update his Facebook page to tell the world they had the wrong man. And now, within the past few hours, a double whammy from CBS and NBC:

CBS News and NBC News retracted reports about the identification of the Washington Navy Yard shooter on Monday, just minutes after each network reported that the suspect in question was a Navy chief petty officer named Rollie Chance.

CBS’s John Miller reported that Chance was a suspect before 1 p.m. on Monday. NBC News later reported the same information and continued to do so past 1 p.m., even after Miller reported that the initial reports about Chance were wrong.

Finally, at 1:05 p.m., NBC political director Chuck Todd tweeted: “NBC News: we are now NOT reporting name of shooter; retracting that report. deleting those tweets.”

I considered omitting the guy’s name here in my own feeble attempt to limit the search-engine damage to him, but given how much attention is being paid to CBS’s and NBC’s mistake, it’s more likely that online readers will stumble across it today in reading about the screw-up, not about him being a potential suspect. At some point public shaming over these errors will cause major media outlets to be more circumspect in passing along breadcrumbs that their cop friends have scraped together for them based on what they know of the facts at that moment. Today isn’t that day, but next time could be. Although, let’s face it, with Twitter increasing the pressure on news bureaus to be fast and first, it probably won’t be.

Via Mediaite, here’s Obama making his first halting remarks about the shooting. Reportedly, the shooter was carrying a pistol, a shotgun, and an AR-15, so expect more from O about “assault rifles” sometime soon.