They had one job

Law-enforcement officials cannot prevent every American crime. The temptation to cheaply point fingers in the wake of tragedy is powerful, and all too easy. That important caveat aside, and the routine diligence and heroism of so many police officers duly acknowledged, we know enough about the Parkland massacre to say, without a doubt, that the ineptitude was legion.

Last fall, the Federal Bureau of Investigation got a tip that Nikolas Cruz had boasted in a YouTube comment, “Im going to be a professional school shooter” (sic, and sick). A Mississippi man told the FBI; it yielded no intervention with Cruz.

Last month, the FBI got a tip from someone close to Cruz, with info on Cruz’s gun ownership, erratic behavior and disturbing social-media posts. A transcript of that call obtained by NBC News Friday revealed that the tipster said: “I know he’s, he’s going to explode,” adding that though Cruz had talked about killing himself, “now he has switched it to, he wants to kill people.” No one followed up. Devastating.

Local authorities, if possible, were even more negligent. Since 2011, area police had filed more than 30 incident reports, many prompted by calls Cruz’s mother made to police after her son’s threats, violent outbursts and other bad behavior.

Not least, an armed sheriff’s deputy failed utterly to do his job by staying outside Marjory Stoneman Douglas High School while Cruz was inside killing students and teachers. Local police officers that came to the scene waited outside, too.

The sheriff may have been mismatched against a young man with a death wish wielding an AR-15, but the job is to serve and protect. Too many professionals failed, and failed fatefully.