Florida School Shooting

The flag above the White House in Washington is lowered to half-staff for the victims of a mass shooting in a South Florida High School, Feb. 15, 2018.

This video screen grab image shows shooting suspect Nikolas Cruz at Broward County Jail in Ft. Lauderdale, Florida, Feb. 15, 2018. The heavily armed teenager who gunned down students and adults at a Florida high school was charged with 17 counts of premeditated murder, court documents showed.

Parents wait for news after a report of a shooting at Marjory Stoneman Douglas High School in Parkland, Florida, Feb. 14, 2018.

Police vehicles block the road to Marjory Stoneman Douglas High School in Parkland, following a shooting that killed 17 people in Parkland, Florida, Feb. 14, 2018. A former student armed with an AR-15 rifle opened fire at the high school, killing at least 17 people, officials said.

A man who was placed in handcuffs by police is loaded into a paramedic vehicle after a shooting incident at Marjory Stoneman Douglas High School in Parkland, Feb. 14, 2018 in a still image from video.

Dr. Igor Nichiporenko, Medical Director Trauma, left, and Dr. Evan Boyer, Medical Director, Emergency Services, speak about treating victims and the suspect at a press conference outside Broward Health North hospital, Feb. 14, 2018, in Deerfield Beach.

Anxious family members wait for news of students in Parkland, Florida, Feb. 14, 2018. A shooting at Marjory Stoneman Douglas High School sent students rushing into the streets as SWAT team members swarmed in and locked down the building.

A man placed in handcuffs is led by police near Marjory Stoneman Douglas High School following a shooting incident in Parkland, Feb. 14, 2018 in a still image from video.

Florida Gov. Rick Scott speaks during a news conference near Marjory Stoneman Douglas High School in Parkland, where a former student is suspected of killing at least 17 people, Feb. 14, 2018.

A woman consoles another at Marjory Stoneman Douglas High School in Parkland, Feb. 14, 2018.

A law enforcement officer tells anxious family members to move back, Feb. 14, 2018, in Parkland, Florida. Police warned that the shooter was still at large even as ambulances converged on the scene and emergency workers appeared to be treating those possibly wounded.

Students are evacuated from Marjory Stoneman Douglas High School during a shooting incident in Parkland, Feb. 14, 2018 in a still image from video.

Students react following a shooting at Marjory Stoneman Douglas High School in Parkland, Florida, a city about 50 miles (80 kilometers) north of Miami, Feb. 14, 2018.