Got the true facts and changed his tune.
Check it out:

Mark Glaze, who just resigned as executive director of Michael Bloomberg’s Mayors Against Illegal Guns (MAIG), now says that the gun control restrictions MAIG supports are “a mismatch,” where crimes committed by mass murderers are concerned. “It is a messaging problem” for gun control supporters “when a mass shooting happens and nothing that we have to offer would have stopped that mass shooting,” Glaze told the Wall St. Journal.