Newtown - Parents of the victims of the Newtown, Conn., massacre tell Scott Pelley that theirs is a lifetime quest to change gun laws in hopes of preventing the gun violence that took their young children. Henry Schuster is the producer. This is a two-part segment. Watch a preview Linsanity - Jeremy Lin shot from obscurity to stardom to become one of the few Asians to play professional basketball in the NBA. His sudden rise and stellar play became known as "Linsanity." Charlie Rose reports. Peter Radovich is the producer