I would not be surprised to find that liberals (so called progressives) have devised deceptions including embellishment of true happenings and outright fiction to support arguments for gun control (and ultimate confiscation). Taking advantage of a crisis for purposes of political gain involves misrepresentation of what really happened AND creation of supporting evidence that is entirely fictional. It also includes suppression (denial of actual happenings or ignoring their existence) of evidence that would prove their version of the story to be false.
Human nature is to believe a story of horror until it is debunked or admitted to be false. Orson Wells certainly proved the gullibility of the nation as a whole with his martian invasion scare.
War of the Worlds: How Orson Welles Drew the Nation into a Shared IIlusion
...and this was with a story that had not a smidgeon of truth to it. None of it happened.
Though I have not seen a single photo of a bullet-riddled body from the Sandy Hook shooting, I have no doubt that it did happen and that the people named were actually killed. The information that has flowed from it regarding specifics is questionable based solely on the tendency of humans to distort the true record of happenings as they repeat what they heard or read about it. When this natural tendency is augmented by a DESIRE to misrepresent the truth, it becomes exponential and generates conspiracy theories such as we have now.