Mayor-President Sharon Weston Broome announced the reworking of the Baton Rouge Police Department's policy guiding how officers can use force while on the job, following through Thursday on part of a major campaign plank to implement changes at the agency.

While BRPD Chief Carl Dabadie Jr. said the department already trains officers in the practices announced by the administration, he agreed that writing them into policy was necessary to ensure that officers who do not follow them can be punished.

Broome's pledge to implement new policies at BRPD was partially spurred by the shooting of Alton Sterling in July by a BRPD officer, an incident that provoked complaints about the police department's interactions within the black community. The shooting, which occurred after two city officers struggled with Sterling outside a north Baton Rouge convenience store, remains under federal investigation.

Criminal justice experts said that the changes put Baton Rouge ahead of many police departments in instituting written policies based on accepted best policing practices. They added that the measures may seem like common sense, but are often not penned into police policy manuals.

The changes, which became effective immediately on Thursday, are:

• Officers must give verbal warnings before using deadly force unless there are extenuating circumstances.

• Officers cannot use force before trying to de-escalate situations when possible. The outlined strategies include disengagement, area containment, waiting on subjects, summoning reinforcements and calling in specialized units.

• Police cannot use chokeholds or strangleholds unless they are in an emergency and do not have other weapons available.

• Police cannot shoot at moving vehicles unless the people inside of them pose immediate deadly threats.

• Officers are now required to intervene to stop their colleagues from using excessive force. They are also required to report when they see another officer use excessive force.

Broome developed the use-of-force policies in closed-door meetings over the past month with an "advisory council on law enforcement" that included community activists, pastors, council members and law enforcement representatives. The policies represent the first major change that a local political leader has successfully made to the department since the Sterling shooting.

"There's a difference between training and putting this in policy, and so now it becomes policy, and policy represents accountability," Broome said at a news conference as her advisory council stood behind her.

The police chief can take any number of disciplinary measures against an officer who violates policy, ranging from small reprimands to firing an officer.

Professional police agencies are moving in the direction of mandating de-escalation, said Dennis Kenney, a professor at John Jay College of Criminal Justice in New York and a former police officer. He pointed to the policy of mandating officers to report excessive force from other officers as one of the most rare.

"Where this becomes important is a case where an officer is found guilty of using excessive force and there were several other officers around, those other officers are now liable as well," Kenney said. "That's a pretty progressive thing on the part of the department. They should really be applauded for that."

Not allowing chokeholds and not shooting at cars are standard practices at most police departments, according to Kenney and Samuel Walker, a professor emeritus at the University of Nebraska at Omaha.

Shooting at cars is "a real danger to innocent bystanders," Walker said.

But Walker, who was written extensively about police accountability and studied many cities' reform efforts, questioned whether Baton Rouge was backward in rolling out policy changes for training that already exists. He said policy should come first, and the policy should dictate training to teach officers what is and what is not acceptable.

He and Kenney also agreed that the policy changes should not hurt officer safety.

"In fact, especially with de-escalation, it's likely to enhance officer safety," Walker said. "If you can enter in a situation and talk it down to a peaceful resolution, it's less likely that the officer is going to be injured."

At BRPD, the practices have previously been more "understandings of this is part of police work and this is what you do" as opposed to written out, Dabadie said.

The existing BRPD "use of force" policy is relatively vague. When arresting suspects, officers should use "only the amount of force necessary to effect the arrest," according to existing policy.

"Employees shall employ deadly force only in defense of their own lives or in defense of the life of another person," the existing policy reads. "It is essential that the employees reasonably believe that he or some other person is in immediate and apparent danger of suffering death or great bodily harm and that the use of deadly force is the only prudent preventative measure available to him."

The true test of the policies will be what happens when an officer violates them, said Franz Borghardt, a Baton Rouge defense attorney.

"This creates a standard that will allow individuals on both sides to bolster their case on why there was or wasn't excessive force," Borghardt said.

But he said it's clear that the policies were the result of compromise, given the "except" and "unless" caveats tucked into each of them. The general language still leaves wiggle room for officers, he said.

When reached Thursday, BRPD Union President Sgt. C. Bryan Taylor said he had not had time to read the policy changes and that he would review them before commenting.

The Metro Council was on a retreat while Broome announced the changes. Council members decided to hold off on discussing the matter; several said afterward that they had not confirmed the details of the mayor's plan or read the list of advisory board members.

Since the Sterling shooting last summer, the Metro Council has discussed possible changes to BRPD policies — which notably included a residency requirement — though no binding measures have passed. Elsewhere, some council members have held meetings with community leaders and academics to brainstorm other possibilities, though no concrete proposals have advanced so far.

Councilman LaMont Cole, a Democrat who serves on Broome's advisory council, praised the mayor's actions, especially as the introduction of body cameras will make the new policies more enforceable. Republican Councilman Trae Welch wondered what affect the new policies will actually have because of the existing training.

Members of Broome's advisory council include Dabadie, Arthur "Silky Slim" Reed, Gary Chambers, Cleve Dunn Jr., State Police Col. Mike Edmonson, East Baton Rouge Sheriff Sid Gautreaux, Constable Reginald Brown, Broderick Bagert of the group Together Baton Rouge and others. Several committee members attended Broome's announcement on Thursday morning and applauded it afterward.

"What if these kinds of policies were in place last July?" said the Rev. Richard Andrus, pastor at St. Paul the Apostle Catholic Church and a council member. "I believe Alton Sterling would still be alive."

A Baton Rouge Police Department internal affairs probe into the Sterling shooting — which will consider whether the officers violated any policies or procedures during their handling of the incident — is pending.

Brief cellphone video footage of the shooting, which circulated widely online, appears to show the officers ordering Sterling against a car and using stun guns before the shooting of the 37-year-old man, who had a gun in his pants pocket. A BRPD report after the shooting said that at least one officer believed Sterling was reaching for the weapon. Additional evidence, including store surveillance footage that could show more of incident, is being reviewed by federal investigators and has not been made public.

While Broome and Dabadie worked together on the new policies, she is continuing to search for a new police chief. The two said that they continue to meet but have not yet reached a resolution, as civil service laws prevent Broome from easily firing Dabadie although she has said she wants to replace him.

Follow Andrea Gallo on Twitter, @aegallo.​