The dangers of live breaking news reporting were in evidence Wednesday as conflicting reports had the airwaves buzzing and the Twitterverse humming with news of an arrest in the Boston Marathon bombing.

CNN’s John King was among the first to break the news that a suspect had been located and, in fact, was in custody in the highly-charged case.

Fox News, the Associated Press, the Boston Globe and some Boston TV stations quickly followed suit.

By trusting anonymous sources in law enforcement — sources who apparently were unauthorized to go on the record about the case — certain media outlets over-reached.

Worse than getting it wrong was CNN’s floating the possibility that the government had leaked bad information intentionally in order to use the media. The speculation seemed self-serving given the context.

Backpedaling on the air, CNN’s King indicated that his law enforcement source ran into “significant blowback at the leaks.”

NBC resolutely declined to confirm the report of an arrest. CBS and ABC likewise held back from reporting the existence of a suspect.

“They have some hot leads,” Pete Williams reported on NBC, but he declined to go further.

“We are just not comfortable reporting that,” Brian Williams said on NBC, referring to an AP report of a suspect in custody.

As emotions rollercoastered through a dizzying afternoon of claims, counter-claims and retractions on cable TV news, CNN backed off its “scoop,” while the Justice Department and Boston law enforcement issued reprimands to CNN and other news organizations for over-reaching.

On CNN in particular, confirmed journalistic reports devolved into speculation, in real time, before the public’s eyes.

Jokers on Twitter had a field day as the entire concept of “breaking” news appeared to manifest all too literally.

Kelsey L. Hayes, a copy editor for Politico, summed up on Twitter: “This giant writhing mass of journalistic derp makes me kinda glad we didn’t have Twitter on Sept. 11.”

By late afternoon a CNN spokesperson issued a statement saying CNN had “three credible sources on both local and federal levels. Based on this information we reported our findings. As soon as our sources came to us with new information we adjusted our reporting.”

News executives at local stations and national networks have long felt pressure to keep pace with the breaking news of competitors. If CNN has it, executives ask, why don’t their staffers?

Maybe because it’s not confirmed.

Joanne Ostrow: 303-954-1830, jostrow@denverpost.com or twitter.com/ostrowdp