'One of everyone's favorite teammates' —
Jovan Belcher had advanced from an undrafted free agent linebacker to NFL starter for the Kansas City Chiefs and played in every game since 2009. On Saturday, December 1, 2012, the 25-year-old star allegedly killed his girlfriend, then drove to the Chiefs' practice facility and took his own life. After the tragedy, teammate Tony Moeaki tweeted, "One of everyone's favorite teammates including one of mine." Here's a look at his career with the Chiefs and tragic end: