No, I'm not without sin when it comes to having to retract a story. But I'm going to cast a stone anyway. Newtown, Boston and now the D.C. Navy Yard. In each case the media went into hyperventilated "we have to be first" mode and made an egregious error. Each time they enter a period of self-loathing and say it won't happen next time. And then, it happens next time.
In this case, the falsely reported suspect had dropped their ID. I have a theory. The media still hasn't recognized that Twitter is really reporting when you identify your employer and report information. They think they understand that but there appears to be a psychological disconnect where they seem to believe "well, it's not like I reported it on TV." I am somewhat informed by experience on this. Until they learn this, there will always be a "next time."