Students outside of Marjorie Stoneman Douglas High School in Parkland, Fla., after the Feb. 14, 2018, shooting.Photo: Gerald Herbert/AP/REX/Shutterstock

The killer in2018’s mass shooting at Marjorie Stoneman Douglas High School in Parkland, Fla., plead guilty Wednesday to all17 murdershe committed that Valentine’s Day, an action that sparked a national student-ledMarch for Our Livesmovement to curb gun violence.
RELATED VIDEO: 3 Years After Parkland Shooting, Survivors Describe How They Have Changed & Call for Gun Reform
Fourteen students and three staff members were killed in the Feb. 14, 2018, attack at the school, which then-Florida Gov. Rick Scott described as an act of “absolutely pure evil.”
Just five weeks after the massacre, a coalition that began with student survivors of the Parkland shooting staged theMarch for Our Lives rallyin Washington D.C., then launched a cross-country caravan to engage local communities in an effort to change gun laws.
Nikolas Cruz in court Feb. 18, 2018.Mike Stocker-Pool/Getty

Among the memorable moments from that rally, studentEmma Gonzalez, who became one of Parkland’s most prominent voices after the shooting,stood silentfor most of her time on stage as a timer counted the 6 minutes and 20 seconds it took the gunman to complete his carnage.
In the aftermath, two women who lost loved ones in the shooting were elected to the Broward County School Board.
One of those women,Debra “Debbi” Hixon, was a longtime educator whose husband, Chris, 49, worked as the school’s athletic director and wrestling coach. When the gunfire on campus erupted, the father and Navy veteran who tried to shield students was shot, and died the next day at the hospital. The other woman, former teacher and athletics coachLori Alhadeff, lost her 14-year-old daughter, Alyssa, in the shooting.
A vigil for victims of the Parkland, Fla., school shooting.Matt McClain/The Washington Post/Getty

Like other parents, Hixon and Alhadeff turned their losses into activism. Alhadeff is president of the national non-profit organizationMake Our Schools Safe, focused on protecting students and teachers at school. Hixon is president of theChris Hixon Athletic Scholarship, dedicated to the memory of her husband.
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“We know our loved ones better than anyone, so we know what is really that thing that we’re missing and they were not able to finish,“Oliver told PEOPLE in 2019.
source: people.com