In the immediate aftermath of the 2009 Fort Hood shooting committed by United States Army psychiatrist Nidal Malik Hasan, Casey expressed concern about jumping to conclusions before the investigation was completed, telling CNN's John King that "this increased speculation could cause a backlash against some of our Muslim soldiers" and "As great a tragedy as this was, it would be a shame if our diversity became a casualty as well." Several months later, in a February 2010 interview, Casey said: "Our diversity not only in our Army, but in our country, is a strength. And as horrific as this tragedy was, if our diversity becomes a casualty, I think that's worse."