A group formed by families who lost children in the Sandy Hook school shooting has started a new public service campaign designed to teach people to recognize the warning signs of someone who may be contemplating gun violence.

  • Sandy Hook Promise released new PSA video
  • Group was started by parents who lost their children in 2012 shooting
  • They hope PSA will illustrate warning signs  

The Know the Signs campaign from Sandy Hook Promise included the launch on Friday of a new 2-minute video public service announcement designed to show how easy it is to overlook at-risk behavior.

The group's founders include Nicole Hockley and Mark Barden. Both had 6-year-old sons who were among the 26 people killed by a gunman inside the Sandy Hook Elementary School on Dec. 14, 2012.

The PSA can be viewed on YouTube, or watch below: