On Tuesday, President Trump signed an executive order calling for, among other things, the establishment of a database on police use of force. On Wednesday, Senate Republicans included a similar provision in their own reform bill. But the FBI already has such a database — and so far a majority of police are not participating in it.

The FBI launched that program, the National Use-of-Force Data Collection project, last year. Now, with another wave of protests against police brutality gripping the country, many police agencies have not responded to the voluntary call for information about their officers — only 40 percent submitted their data for 2019, the FBI said. And the database has yet to be published. The first report is planned for this summer.

In his executive order on police reform issued Tuesday, President Trump called for “a database to coordinate the sharing of information” among law enforcement agencies on “instances of excessive use of force related to law enforcement matters,” and said the attorney general “shall regularly and periodically make available to the public aggregated and anonymized data from the database.” It was not immediately clear if the FBI’s use-of-force project will be the vehicle for that order.

Trump’s order also states that federal funds should be withheld if a police department doesn’t submit its data, as does the reform bill submitted by Senate Republicans on Wednesday.

For decades, the FBI has collected crime data from police departments across the country, in its Uniform Crime Reports, and participation in that program is nearly 100 percent. But as with the annual crime reports, participation in the use-of-force project is voluntary.

In a statement to the Senate Judiciary Committee on Tuesday night, Steven R. Casstevens, the chief of the Buffalo Grove, Ill., police and president of the International Association of Chiefs of Police, said that “participation in the national database collection effort should be mandatory.” He said the data would help both law enforcement and the community “better identify and understand the totality of incidents, trends associated with use-of-force incidents, and other outlying factors. It will also increase transparency on a national level.”

Casstevens said making use-of-force reporting mandatory might mean tying it to existing federal grant funding, and he said the “IACP recommends those that intentionally fail to participate in the National Use of Force database, be excluded from receiving federal grant funds or receive reduced amounts.”

A little over a year ago, at a meeting of the Major Cities Police Chiefs Association in Miami Beach, the head of the FBI’s Criminal Justice Information Services Division subtly implored her audience of top police executives to get on board. At that May 2019 meeting, Amy Blasher told the chiefs that as of that month, 19.6 percent of the nation’s departments were participating, or about 2,200. Thirty-nine of the 69 U.S. cities in the Major Cities group had filed data then, Blasher said.

She also reassured the chiefs that the project would not release any individual agency’s data to the public, though each agency’s crime data is released in the Uniform Crime Reports.

But Blasher said there would be a public list of which agencies contributed. The FBI has so far declined to release a list of which agencies participated in 2019.

FBI spokeswoman Holly Morris last week said, “The goal of this collection is not to offer insight into single incidents, but to provide a comprehensive view of the circumstances, subjects, and officers involved in use-of-force incidents nationwide.” She did not respond to a question about how the data can be interpreted on a national level without nationwide police participation.

Richard Rosenfeld, a criminologist at the University of Missouri at St. Louis, said of the 40 percent participation rate, “My strong hunch is it’s the much smaller agencies, that have had no use-of-force incidents that qualify, that are simply not responding.” But knowing which agencies aren’t using force on citizens is also important to know, Rosenfeld said. “And there’s no requirement to respond,” he added.

The FBI effort followed the high-profile police shootings of unarmed African Americans, including the 2014 killings of 18-year-old Michael Brown, who was shot in Ferguson, Mo., and 12-year-old Tamir Rice, who was shot in Cleveland, both by white police officers. There were other controversial deaths in police custody around that time that did not involve shootings. As law enforcement officials acknowledged that the full scope of how and when officers used force was unknown, citizens called for greater transparency.

In 2015, The Washington Post created a database to track fatal police shootings across the country. That year, 994 fatal police shootings were counted by The Post. In subsequent years, the totals have ended between 962 (in 2016) and 1,002 fatal police shootings (last year). So far this year, the total is 481.

The Post’s database tracks only fatal police shootings, not any other uses of force by police and not deaths caused by other means, such as the asphyxiation death of George Floyd in Minneapolis. Police officials have cited The Post’s data as something that law enforcement should be gathering itself. The Post relies on Internet searches of media reports and public records requests to gather its data.

There are three types of incidents the FBI wants to track: fatalities by law enforcement, serious bodily injury by law enforcement, and firearms discharged at or in the direction of a person by law enforcement. The FBI cited a study which found that officers miss their target about 50 percent of the time in firing range tests, thus the need to track shootings with no injury.

Within each incident, the FBI is asking for 28 data points, including the demographics of the officer and the subject, the type of force used, the threat posed (if any), the initial reason for the call and whether the subject was impaired by drugs, alcohol or mental health issues.

As a test, the FBI launched a pilot program for six months in 2017, and enlisted 98 local and federal agencies to participate, 24 of which had at least 750 officers or agents. Even then, about 70 percent actually submitted their data. With reminders and phone calls, the FBI eventually got 90 percent of the agencies to file. The FBI would like agencies to file their previous month’s reports, or “zero reports” if no incidents, by the 15th of each month, but retroactive filing is also accepted.

In a report on the pilot project, the FBI said it asked the agencies why they hadn’t filed data. Some said getting into the restricted data entry portal was “a hassle,” or that their own department’s firewall caused problems. Some said workload or time constraints made them choose not to participate after initially volunteering. Some raised issues with some of the finer data points requested, such as the “height and weight of the officer,” which the agencies sometimes said they didn’t track. The FBI estimated in a filing in the Federal Register that it took about 38 minutes to enter the data for each incident.

In that report, and in plans for the national use-of-force data, the FBI said its first data collection publication was scheduled for March 2019. The agency expected lower participation at first, so it planned to publish the status of all participating states. Many local police submit their Uniform Crime Report data to state police, who gather it from all the departments and submit it to the FBI.