Sandy Hook Promise, formerly known as Newtown United, plans to announce the initiative Monday.
The group said Friday it invited victim family members to the event.
A co-founder of the group, Tim Makris, said he doesn't have a count of how many families might participate.
He said the families are at varying stages of grief and recovery, and some may never want to discuss the issues.
A gunman shot his way into Sandy Hook Elementary School on Dec. 14 and killed 20 first-graders and six women before committing suicide as police arrived. He also killed his mother before driving to the school and carrying out the massacre.
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