KANSAS CITY, Mo. (AP) — Jamaal Charles is carrying the football these days with a heavy heart. The Chiefs’ running back was friends with linebacker Jovan Belcher, and helped introduce Belcher to his wife Tiffany’s cousin, Kasandra Perkins. Two weeks ago Saturday, Belcher fatally shot Perkins and then killed himself. Charles hasn’t spoken publicly since the incident, but he’s still turning out big performances on the field. He leads the AFC with 1,220 yards rushing, and his four carries of 40-plus yards this season are tied for second-most in the NFL.That makes Charles a bright spot in a bleak season for the 2-11 Chiefs, who play at Oakland this weekend.