Boston University researchers found the disease in his brain .
In February 2011 , former Chicago Bears defensive back Dave Duerson , 50 , committed suicide with a gunshot to the chest , rather than his head , so his brain could be researched for CTE .
Boston University researchers found the disease in Dave Duerson 's brain .
In February 2011 , former Chicago Bears defensive back Dave Duerson , 50 , committed suicide with a gunshot to the chest , rather than his head , so his brain could be researched for CTE .