Family and friends mourning a federal law enforcement officer who was fatally shot while guarding a U.S. courthouse in Oakland voiced poignant pleas Friday for an end to the violence that cut short his life, saying America needs to overcome discrimination and hatred. David Patrick Underwood, 53, was remembered as a soft-spoken and gifted natural athlete, a lefty pitcher in high school who was valiant on the mound and graceful on the basketball court. In life and in work, he was confident but never arrogant, friends and family said in moving tributes. He treated people with dignity and had a...