As many as 200 of the nation’s most prominent police chiefs, Justice Department and White House officials, and police training experts convened in Washington on Friday to discuss policy proposals which, if implemented broadly, would amount to the most drastic police reform in decades.

During the forum, titled “Taking Policing to a Higher Standard," top officials from many of the nation’s largest police departments were urged to implement new training and departmental policies that supporters believe could lead to a decrease in the number of fatal shootings by officers each year — a topic near the top of the national consciousness in the 18 months since the shooting of Michael Brown in Ferguson, Mo.

“This is a defining moment for us in policing,” Charles Ramsey, the recently-retired commissioner of the Philadelphia Police Department, told the room. Ramsey, also a former D.C. police chief, was one of several prominent policing officials who said departments must act proactively to change their use-of-force policies instead of waiting for one of their officers to be involved in a controversial shooting.

“We need to raise the bar for all police departments,” Chuck Wexler, who runs the Police Executive Research Forum, a policing policy think-tank that organized the gathering, told the Washington Post .

Accurate national statistics on fatal police shootings were unavailable until last year when The Washington Post launched a database to track them, documenting 987 fatal shootings by on-duty officers in 2015 .

Wexler presented The Post’s findings to the gathering of officials and said that even after removing all shootings in which the person killed had a gun, there were still hundreds of preventable fatal shootings last year.

“We can impact about 300 of those,” he said.

Among reforms discussed at length were retraining all officers in deescalation tactics and abandoning training that teaches the “21-foot-rule” — a turn of phrase taught to nearly all current U.S. police officers that is often interpreted by officers to mean they are justified in shooting any suspect with a knife or edged weapon who comes within 21 feet of them.

The suggested guidelines were released as a PERF report titled "Use of Force: Taking Policing to a Higher Standard."