It was a sadly familiar scene.

A mother in East Flatbush called 911 on Monday afternoon about her mentally troubled son, who she identified as behaving erratically but not violently. Four officers responded, according to the police account, and she opened the door and ran to the back of the apartment saying, “He’s back here.”

Dwayne Jeune, 32, ran into the living room with a steak knife, Chief of Patrol Terence Monahan told reporters on Tuesday. One officer activated his Taser, but Jeune didn’t stop. That officer backpedaled, was knocked down by Jeune, who stood over him with the knife, Monahan said. Then another officer shot in the chest.

The questions began immediately after Jeune’s death, which was similar to those of other emotionally disturbed people who have been killed in confrontations with police, from Eleanor Bumpurs in 1984 to Deborah Danner in 2016: Could the officers have done anything different? What training, if any, might have changed the outcome this week? And mostly, why did the bloody scene repeat?

Another shooting, another set of questions

Jeune’s death is being investigated by the department, but for now, there may be just as many questions as answers.

The NYPD handles about 400 mental crisis calls a day, according to a January report from the NYPD inspector general. Those calls are mostly handled without serious consequences, but they can be some of a police department’s most difficult work: Nationally, a quarter of the 991 people killed in confrontations with police in 2015 exhibited signs of mental illness, according to the report.

The NYPD has taken some steps to prevent fatal police-civilian encounters of this kind. That includes the increased deployment of Tasers, which were ignored for a gun in the Danner case last year. But even if used, Tasers can result in injury or death on their own, and they are no magic solution: as happened on Monday, the weapons can fail to function if the weapon’s prongs don’t hit in particular ways or at certain distances from each other.

So the NYPD has often relied on training, the most widespread version of which is called Crisis Intervention Training, a decades-old model used nationally that the NYPD slowly began adopting in 2015.

The idea is to teach officers how to de-escalate encounters with the mentally ill, understanding more about how they react to police and how police might change their usual practices to come out of an encounter safely for all.

“The whole thing with CIT is to be tactic-ful and tactful,” says Capt. Mark Turner, one of the NYPD’s CIT trainers.

The program has been found to reduce arrests and use of force, according to multiple studies, yet critics say the NYPD hasn’t trained enough officers to do the job: At the start of summer, just over 5,500 had received the training. Sgt. Hugh Barry, now charged with murder in Danner’s shooting, had not.

Three of the officers who responded to Flatbush Gardens on Monday had received the training, according to the NYPD. But not the officer who fired his weapon, Miguel Gonzalez.

Can training make a difference?

Gonzalez, in fact, had been involved in a shooting in Brooklyn in October, involving a man who the police had not been told was bipolar advancing on officers. The man had a knife, and Gonzalez shot him (the man survived).

Commissioner James O’Neill said Monday that the investigation of Gonzalez’s previous shooting was still open, but added his preliminary judgment of that case: “We see that shooting as within guidelines.”

Neither he nor Mayor Bill de Blasio would say whether Monday’s shooting was appropriate, pending an investigation.

But could CIT training, if Gonzalez had received it, have changed the outcome? Turner, the CIT trainer, didn’t know the full details of Jeune’s death in Brooklyn and couldn’t speak to specifics.

“What we try to tell cops is remain a fair distance away,” Turner said, plus not advancing toward a person without cause in a weaponized situation. But if Jeune was indeed going toward the officers with a knife and they couldn’t “maneuver away,” and if the officer deployed a Taser without effect and the individual is advancing, “your options are running out,” Turner said.

Turner said it was important for civilians to know they could trust the police and give them a full picture of what was going on when they called 911. “It’s OK if the person is a little bit aggressive,” said Turner. “We’re not there to judge you.” Using and reacting to such information expertly is the point of CIT. There are also resources for violence-prone scenarios. Ultimately, it’s important that residents should feel comfortable going to the police, Turner said, and then “let them, the officers, deal with it.”