1. He had a “desire to kill.”

That’s what a tipster told the F.B.I. about Nikolas Cruz, the Florida school shooting suspect, last month. But the agency didn’t follow through on the tip.

In an unusually sharp public rebuke of his own agents, Attorney General Jeff Sessions said that the missed warnings had had “tragic consequences” and that “we must do better.” Gov. Rick Scott called for the bureau’s director, Christopher Wray, to resign.

Funerals for some of the 17 victims in Parkland, Fla., have begun, while schools across the U.S. closed their doors or tightened security after threats or rumors of coming violence. Here’s the latest.