In the early days after Mark Barden’s first grade son Daniel was gunned down at Sandy Hook Elementary School, his family hunkered down in their home, drowning in grief.
Relatives filled their house, offering comfort and trying to protect the Bardens from the media that swarmed Newtown, Conn., to cover the grizzly aftermath of a gunman killing 19 other first-graders and six adults. Barden was still trying to grasp the unthinkable loss of his 7-year-old when his landline rang. It...