Once inside, as he loaded his rifle, he happened across a student. “You better get out of here,” he warned him. “Something bad is about to happen.”
Then he began to shoot. His rampage, which lasted just under six minutes, took the lives of 14 students and three faculty members.
Killed in the shooting were Alyssa Alhadeff, 14; Scott Beigel, 35; Martin Duque, 14; Nicholas Dworet, 17; Aaron Feis, 37; Jaime Guttenberg, 14; Christopher Hixon, 49; Luke Hoyer, 15; Cara Loughran, 14; Gina Montalto, 14; Joaquin Oliver, 17; Alaina Petty, 14; Meadow Pollack, 18; Helena Ramsay, 17; Alex Schachter, 14; Carmen Schentrup, 16; and Peter Wang, 15.
Mr. Cruz killed the 17 victims and injured 17 others without entering a single classroom. Instead, he took aim at students and teachers trapped in the hallways or locked inside classrooms, shooting at them from the door. Several times, he returned to people he had already wounded to shoot them dead.
He left the school undetected and was arrested about an hour later, walking down a residential street.
The shooting began a national gun control movement fueled by student activists. The Florida Legislature adopted some gun restrictions, which Rick Scott, the Republican governor at the time, signed into law.