First, do not pass on speculation. For much of the day, the New York Post was sharing unconfirmed reports, which were later proven erroneous, that 12 people had been killed in the attack. I actually retweeted BuzzFeed’s Andrew Kaczynski, one of the smartest and most conscientious journalists on Twitter, and repeated this tidbit on the official Slate account. In hindsight, it would have been wiser for both of us to broadcast that news in more skeptical terms.

At times, I have succumbed to the desire to be the first source to pass along a story, and I’ve gotten burned. Slate was one of the first outlets to tweet out that we had found the likely Facebook page of the man who was then being reported to be the Newtown shooter, Ryan Lanza. Shortly after that report, it was discovered—by, ironically, the New York Post among others—that the shooter wasn’t Ryan, but his brother Adam. In reporting that CNN’s Susan Candiotti had named Ryan as the shooting suspect, I was very cautious to cite a mainstream source. It turned out that the source was wrong, and this was one of the most embarrassing mistakes I’ve made as a journalist. —Slate Magazine.