A call to an anonymous tip line set off a chain of events that helped thwart a potential Valentine’s Day mass shooting in Indiana, authorities say.

Indiana Teen Obsessed with Mass Shooters Arrested for Planning School Shooting, Trinity Shockley, Mooresville High School, active shooter

The group Sandy Hook Promise, born out of the 2012 Newtown tragedy, cites its anonymous threat-reporting system for stopping a planned mass shooting. The tipster had concerns the suspect had been planning an attack on Mooresville High School in Indiana for Valentine's Day,

After allegations surfaced against a Mooresville High School student arrested for planning a school shooting, WRTV spoke with Nicole Hockley, co-founder of Sandy Hook Promise.

A tipster claimed Trinity Shockley, 18, “has access to an AR15 and has just ordered a bulletproof vest,” NBC News reports, citing a probable cause affidavit.