Sandy Hook Promise has launched a national, anonymous reporting system to root out school violence.  It's the Say Something crisis hotline.  Co-founder Mark Barden says 80 percent of school shooters told someone about their plan before they carried it out.  The call center is staffed 24/7 with trained experts who can then vet and prioritize information and then report to authorities.  This builds off the organization's Say Something initiative.  The free school-based program teaches students the warning signs that a peer is about to commit violence.  Barden says he'd rather have 100 false alarms if means 1 tip leads to an intervention.  Students can submit an anonymous tip online or by phone.