The police killing of George Floyd a month ago is prompting new scrutiny of the three officers who failed to intervene before the handcuffed suspect lost consciousness and died as he was pinned to the pavement by a veteran officer.

"You watch this scene and ask yourself, why do they stand by?" said Chuck Wexler, executive director of the Police Executive Research Forum in Washington, D.C., and national authority on police practices. "When is it going to change so that intervening is considered doing the right thing?"

Several experts in police psychology and behavior, including some top police officials, say Floyd's death is indicative of a larger problem: a tendency of officers to not question and intervene when another officer — particularly a senior officer — uses excessive force.

"When you intervene, you have the ability to potentially save a life or a career," Shaun Ferguson, superintendent of the New Orleans Police Department, wrote in a staff memo.

Training officers how and when to intervene, while mandatory in New Orleans and being developed by other law enforcement agencies nationwide, is not done in Minneapolis.

Erik Misselt, interim executive director of the Minnesota Peace Officer Standards and Training (POST) board, which does initial training of officers and issues licenses, said he's unaware of any law enforcement peer intervention training in the state.

"We don't have anything in the state of Minnesota that is that specific," Misselt said, although there is training on how officers can keep themselves in check. The board will review programs to consider possible changes, he said.

During last week's special session, the Legislature stalemated on proposals for police reform, including a requirement for officers to intercede. None of the bills would have required training officers when and how to intervene to stop misconduct.

For nearly eight minutes, Officer Derek Chauvin knelt on Floyd's neck. Floyd's death led to murder charges against Chauvin, plus aiding and abetting murder charges against the three officers who assisted in the arrest.

Experts in police psychology and behavior, including some top police officials, say Floyd's death was preventable.

"All of this could have been avoided if one or two of his fellow officers intervened," Ferguson wrote in his staff memo.

Chauvin was a training officer for two of the rookie officers who were charged with aiding and abetting murder: J Alexander Kueng and Thomas Lane.

Al Berryman, former president of the Minneapolis Police Federation and a retired sergeant, said officers were not trained on how to intervene in such situations. A new officer assigned to a trainer would be reluctant to intervene because the trainer could write him up, he said. "It could affect your probation."

Before Floyd's death, the Minneapolis Police Department had a rule stating that officers had a duty "to either stop or attempt to stop another sworn employee when force is being inappropriately applied or is no longer required."

On June 16, Minneapolis Police Chief Medaria Arradondo revised the rule in an e-mail sent to police supervisors.

"Regardless of tenure or rank," the e-mail says, "any sworn employee who observes another employee use any prohibited force, or inappropriate or unreasonable force (including applying force when it is no longer required), must attempt to safely intervene by verbal and physical means. Employees who attempt to safely intervene shall not be subject to discipline to the same severity as if they themselves engaged in the prohibited, inappropriate or unreasonable use of force."

The penalty for failing to intervene ranges from coaching and a disciplinary letter to termination. The POST Board will vote July 23 on a stronger policy establishing a duty to intervene.

Former Hennepin County Sheriff Rich Stanek, now a consultant, says an intervention policy is insufficient. "A policy must be followed up with training that is scenario-based," he said.

Few departments in the United States train officers on how to intervene in such situations, though the number is growing in the wake of Floyd's death. There's been a surge of interest in the New Orleans Police training program known as EPIC, which stands for Ethical Policing is Courageous.

"The 'duty to intervene' law has been there for a long time," said Jonathan Aronie, federally appointed monitor of the New Orleans police. "It is one thing to say there is a duty to intervene. EPIC teaches you how."

Since the introduction of EPIC, incidents of deadly force and the firing of police weapons were down significantly, according to a 2019 report on the agency. Complaints from the public also fell.

Aronie's firm helped underwrite creation this month of the Active Bystandardship for Law Enforcement Project at Georgetown University to train officers in how to intervene. About 100 law enforcement agencies, some of them large, have asked to be part of the training, Aronie said.

Baltimore, Philadelphia and Boston are among the cities whose police departments have announced plans to adopt an EPIC-like program.

The state of Washington plans to begin such intervention training for all officers, says Sue Rahr, executive director of the Washington State Criminal Justice Training Commission.

"Just making a rule is not enough to compel people to follow it," Rahr said. "What we are seeing across the nation is not a failure of rules and laws, it's a failure of culture," she said. "If you have a new recruit who observes a training officer is doing something wrong, that recruit needs to know that he'll be supported by intervening." In New Orleans, officers get an annual eight-hour class that includes role playing, and other classes as well. Deputy Chief Paul Noel said that if someone with a lower rank sees him do something wrong, he expects that officer to tell him to stop.

"It's a contract we have with each other," Noel said. "Part of the training is for officers to learn is that good teamwork doesn't mean going along with whatever your fellow officer does, but to intervene when the officer does something unethical, unnecessary," he said.

John Locke, a retired Minneapolis police sergeant, trained officers in Minneapolis for 25 years. He said when a young officer is on probation, his task is to observe and ask questions.

Locke noted that Thomas Lane, one of the officers who assisted with Floyd's arrest, had twice suggested that they roll Floyd onto his side so that he could breathe.

Chauvin refused.

So what was Lane supposed to do, throw Chauvin off and roll him over anyway? Locke asked.

"It doesn't happen," he said.