Why was Fort Hood left off the list of mass shootings?

TRANSCRIPT: We have wept with you,' Obama says in Newtown speech

"Since I’ve been President, this is the fourth time we have come together to comfort a grieving community torn apart by a mass shooting. The fourth time we’ve hugged survivors. The fourth time we’ve consoled the families of victims. And in between, there have been an endless series of deadly shootings across the country, almost daily reports of victims, many of them children, in small towns and big cities all across America - victims whose - much of the time, their only fault was being in the wrong place at the wrong time.

"But that can’t be an excuse for inaction. Surely, we can do better than this. If there is even one step we can take to save another child, or another parent, or another town, from the grief that has visited Tucson, and Aurora, and Oak Creek, and Newtown, and communities from Columbine to Blacksburg before that - then surely we have an obligation to try.

History of Mass Shootings

November 2009 - U.S. army psychologist Major Nidal Hasan opened fire at a military base in Fort Hood, Texas, leaving 13 dead and 42 others wounded.
January 2011 - a gunman opened fire at a public gathering outside a grocery in Tuscon, Arizona, killing six people including a nine-year-old girl and wounding at least 12 others. Congresswoman Gabrielle Giffords was severely injured with a gunshot to the head.
July 2012 - Masked gunman opens fire at midnight cinema screen of new Batman film The Dark Knight Rises, killing 12 and injuring 58. Suspect James Holmes is arrested by oplice and awaiting trial.
August 2012 - Gunman kills six people at SIkh temple in Wisconsin before being shot dead by police. Suspect is named as white supremacists Wade Michael Page.