On Friday, Broward County Sheriff Scott Israel revealed that his office received calls, for two years, about Nikolas Cruz before he opened fire on a Florida high school on Wednesday.
According to The New York Times, Israel said his office received about 20 calls in total about the reportedly troubled teen.
In a tweet after the shooting, President Donald Trump called on Americans to report individuals like Cruz:
So many signs that the Florida shooter was mentally disturbed, even expelled from school for bad and erratic behavior. Neighbors and classmates knew he was a big problem. Must always report such instances to authorities, again and again!
— Donald J. Trump (@realDonaldTrump) February 15, 2018
Israel's announcement came as the FBI admitted it failed to properly notify a Miami field office of a warning from someone close to Cruz.
That prompted Florida Gov. Rick Scott to call on Friday for FBI Director Christopher Wray's resignation.
“Seventeen innocent people are dead and acknowledging a mistake isn't going to cut it,” Scott said.
After Cruz allegedly killed 17 people, details started to emerge about his dark background.
Cruz was a former student at Marjory Stoneman Douglas High School, where his shooting occurred, but was expelled for disciplinary reasons.
Jim Gard, Cruz's former teacher, recalled hearing how Cruz was unable to wear a backpack on campus and threatened other students.
He also reportedly posted online messages like “I wanna die Fighting killing s**t ton of people.”
One of his former classmates claimed Cruz “shot guns because he felt it gave him, I guess, an exhilarating feeling.”
According to the Associated Press, Cruz participated in an air-rifle program funded by the National Rifle Association. He trained with a small varsity team after class and would travel to compete at other schools.
“He had an AR-15 he talked about, and pistols he had shot,” 20-year-old Aaron Diener, who drove Cruz to shooting competitions, said. “He would tell us, 'Oh, it was so fun to shoot this rifle' or 'It was so fun to shoot that.'”