Jevon Belcher

Inside linebacker Jovan Belcher of the Kansas City Chiefs in action during the game against the Cincinnati Bengals at Arrowhead Stadium on November 18, 2012 in Kansas City, Missouri.  (Photo by Jamie Squire/Getty Images)

NFL Player’s Murder-Suicide Raises More Questions About Head Injuries

Speculation on Monday continued as to what caused an NFL player to snap, reportedly killing his girlfriend before taking his own life over the weekend.