A group that monitors hate speech and extremism alerted the FBI in July to disturbing internet posts and activity that have now been tied to the 16-year-old Evergreen High student who shot two classmates last week before taking his own life, 9NEWS Investigates has learned.

The tip from the Anti-Defamation League did not include Desmond Holly’s identity or location because the group had not been able to establish either one – but the FBI began investigating.

The tip went to the FBI’s New York field office, according to law enforcement sources familiar with the investigation.

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