More than a month before 17 people were killed at a Florida high school, the FBI got a tip warning that the suspect wanted to kill people and was planning to carry out a school shooting.

The tipster also said Nikolas Cruz owned guns, was acting erratically and had made disturbing social media posts.

The information provided by the caller should've been assessed as a potential threat to life and passed to a field office, the FBI said. But it never reached agents in Florida and no investigation was launched.

It was one of hundreds of thousands of tips received annually by the FBI's public tip li...