Classmates who knew Nikolas Cruz said he was troubled.
A report Department of Children and Family Services obtained by The Sun-Sentinel and confirmed to ABC News by a Broward County Public Defender claimed Crus cut himself in September 2016 and shared video of his wounds on Snapchat.
According to the report, Cruz also said he wanted to get a gun in the video.
"Every sign that you're asked to look at was there," said Broward County Public Defender Howard Finklestein.
The DCF report also showed that Cruz had a history of autism, ADHD, depression, and was on medication. Cruz's public defender said his client had stopped taking the medication.
The FBI never investigated tips it received in January. A local sheriff said his office had responded to 20 calls related to Cruz.
The shooting sparked protests Saturday as surviving students and community members called for changes to gun laws.
"No one should be able to buy an AR-15. No one," said teacher Melissa Falkowski. "Especially not an 18-year-old."
Cruz had just turned 18 when he bought the semi-automatic weapon he used in the shooting.