Barack Obama was sworn in as America's 44th president 1,425 days ago. Since then, five of the 12 deadliest mass shootings in our history have happened. Here they are, as well as other lesser mass gun-killings that happened under his watch.

Before he walked into a Binghamton immigration center and shot 13 people to death last Friday, Jiverly Wong sent a letter to a Syracuse TV station, explaining his motives. He is a courteous, crazy man.