Nikolas Cruz jumped out of an Uber car and walked toward building 12 of the Marjory Stoneman Douglas High School, carrying a black duffel bag and a black backpack. A man inside the school spotted Cruz and knew he was a former student, a troubled kid. He radioed a co-worker, and within a minute heard gunshots.

At least 1,000 people attended a candlelight vigil Thursday night for the 17 people killed in a Florida school shooting, some of the mourners sobbing openly as the victims' names were read aloud.