A year after the school shooting in Parkland, Fla.

Mechelle Boyle hugs a student as they wait for news after the mass shooting at Marjory Stoneman Douglas High School.

Students gather Feb. 16, 2018, at a memorial in Parkland, Fla., to remember those who were killed and injured in the shooting.

Thousands gather for a vigil at Pine Trails Park in Parkland, Fla., to remember those who were killed and injured in the shooting.

Majory Stoneman High School student Cameron Kasky addresses students as they rally Feb. 21, 2018, at the school following a county-wide school walkout.

A student gets a hug as she leaves Marjory Stoneman Douglas High School after attending classes for the first time since the shooting.

Students rally in front of the White House on March 14 to protest gun violence.

Andrew Pollack, flanked by his sons, speaks during a listening session on gun violence with President Trump, teachers and students at the White House on Feb. 21, 2018. Pollack’s daughter Meadow was killed in the Marjory Stoneman Douglas High School shooting in Parkland, Fla.