Trump briefly emerged from hiding to blame a grieving community for its own tragedy.

Wednesday’s shooting at Marjory Stoneman Douglas High School in Parkland, Florida is the 18th school shooting of 2018 and tied for third-deadliest in U.S. history.

While NRA-backed politicians are broadly repeating the cycle of refusing to blame guns, Trump is taking it further.

Thursday morning, Trump criticized the people of Parkland for not “reporting” the gunman to the authorities.

“So many signs that the Florida shooter was mentally disturbed, even expelled from school for bad and erratic behavior,” he wrote. “Neighbors and classmates knew he was a big problem. Must always report such instances to authorities, again and again!”

This degree of victim-blaming is particularly galling, because this was a case in which many people suspected he was a risk and took action to keep others safe.

As even Trump noted, Nikolas Cruz, the suspect, has a social media profile that fetishizes guns and killing. He was expelled for disciplinary issues, including threatening students.

School administrators warned teachers to “keep an eye” out for him, and he was banned from carrying a backpack onto the premises. Cruz even boasted in a YouTube comment that he was going to be a “professional school shooter,” prompting a fellow user to file a report with the FBI, but nothing came of it.

The problem is not, as Trump claims, that people didn’t do anything. They did. It didn’t prevent Cruz from obtaining a deadly weapon and murdering his former classmates.

According to law enforcement, Cruz purchased his AR-15 legally a year ago, in a state where gun laws are relatively lax. Even if Cruz did go through a background check, the FBI does not collect enough information to have flagged him. Nothing in current reports indicates he had been convicted of a felony, was under an indictment or protective order, a known substance abuser, or dishonorably discharged, and while he had previously been under treatment for mental illness, that does not get flagged unless it is court-ordered.

Trump and the GOP seem wholly uninterested in the slightest expansion of background check data. In fact, Trump undid a policy from President Obama broadening mental illness checks last year, and earlier this week, his budget blueprint called for cutting federal gun background check funding by $12 million.

It is clear that Trump will not do anything meaningful to address this tragedy. But blaming this tragedy on the community he failed to protect is particularly disgusting.