Every year, the FBI releases a report that is considered the gold standard for tracking crime statistics in the United States: the Crime in the United States report, a collection of crime statistics gathered from over 18,000 law-enforcement agencies in cities around the country. But according to an analysis by FiveThirtyEight, the 2016 Crime in the United States report — the first released under President Trump’s administration — contains close to 70 percent fewer data tables than the 2015 version did, a removal that could affect analysts’ understanding of crime trends in the country. The removal comes after consecutive years in which violent crime rose nationally, and it limits access to high-quality crime data that could help inform solutions.

Published under the auspices of the Uniform Crime Reporting Program, the Crime in the United States report contains national data on homicides, violent crimes, arrests, clearances and police employment that has been collected since the 1960s. The UCR’s report is an invaluable resource for researchers who track national crime trends and is a rich reference database for journalists and members of the general public who are interested in official crime statistics. Among the data missing from the 2016 report is information on arrests, the circumstances of homicides (such as the relationships between victims and perpetrators), and the only national estimate of annual gang murders.

Tables, by category, in the FBI’s Crime in the United States report, 2015-16 NUMBER OF TABLES CATEGORY 2015 2016 CHANGE Arrests 51 7 -44 Context for crimes* 23 6 -17 Crimes† 25 17 -8 Police dept. employee counts 12 7 -5 Clearances 4 1 -3 Total 115 38 -77 * Expanded offense data beyond the aggregate number of crimes reported by law enforcement.

† Aggregates of the number of violent and property crime offenses reported by law enforcement. Source: FBI

Changes to the UCR’s yearly report are not unheard of, and the press release that accompanies the 2016 report, which was published in late September, acknowledges the removal of some tables, saying that the UCR program had “streamlined the 2016 edition.” But changes to the report typically go through a body called the Advisory Policy Board (APB), which is responsible for managing and reviewing operational issues for a number of FBI programs. This time they did not.

In response to queries from FiveThirtyEight about whether the changes to the 2016 report had been made in consultation with the Advisory Policy Board, a spokesman for the UCR responded that the program had “worked with staff from the Office of Public Affairs to review the number of times a user actually viewed the tables on the internet.” When FiveThirtyEight informed a former FBI employee of the process, he said it was abnormal.

“To me it’s shocking that they made these decisions to publish that many fewer tables and they didn’t make the decision with the APB,” James Nolan, who worked at the UCR for five years and now teaches at West Virginia University, told FiveThirtyEight.

Nolan called the FBI’s removal of the tables for lack of web traffic, “somewhat illogical.” (A spokesman for the UCR program told FiveThirtyEight that in the last year, the UCR received 3,045,789 visitors.)

“How much time and savings is there in moving an online table?” Nolan said. “These are canned programs: You create table 71 and table 71 is connected to a link in a blink of an eye.”

These removals mean that there is less data available concerning a perennial focus of Trump and his attorney general, Jeff Sessions: violent crime. Trump and Sessions have frequently talked about MS-13, a gang with Salvadoran roots, as a looming problem in the country. MS-13 has been cited in 37 Department of Justice press releases and speeches in 2017, compared to only nine mentions in 2016 and five in 2015. Sessions gave a speech on the organization last month, while Trump gave a speech on Long Island in July, saying the gang had “transformed peaceful parks and beautiful quiet neighborhoods into bloodstained killing fields. They’re animals.” Trump also frequently refers to gun violence in Chicago, and at the beginning of his presidency, he established a Victims of Immigration Crime Engagement Office, which aims to study and promote awareness of crimes committed by immigrants who entered the country illegally.

Although the removal of the tables makes it more difficult to get information on one of the White House’s most prominent causes, it also seems like part of a trend in the Trump administration: the suppression of government data and an unwillingness to share information with the press and public. About two weeks after Hurricane Maria devastated Puerto Rico, the FEMA website stopped displaying key metrics relating to island residents’ access to drinkable water and electricity. The data was later restored. The early days of the Trump administration were marked by reports that federal agency employees had been instructed not to talk to the press and to restrict social media postings.

Since Trump took office, government watchdog groups have been concerned about access to government data and maintaining the integrity of that data. Before Trump’s inauguration, Louis Clark, the executive director and CEO of the Government Accountability Project, an organization that protects whistleblowers, told FiveThirtyEight that he worried that the public information offices in various agencies could interfere with transparent sharing of information with the public.

The fact that the FBI Office of Public Affairs rather than the Advisory Policy Board determined which data tables to remove hearkens back to patterns of suppression from the George W. Bush administration. “They set up all these PR operations,” Clark said about the Bush administration’s tactics. “If a reporter called up and wanted to know about the Arctic, the scientists getting the question couldn’t answer and were required to send the reporter to the government PR person.”

The data missing from the report is mostly about arrests and homicides. There were 51 tables of arrest data in the 2015 report, and there are only seven in the 2016 report. Data about clearance rates — essentially the percentage of crimes solved — was covered in four tables in 2015 but just one in 2016. The expanded offense data — information collected by the FBI beyond the number of crimes committed, such as the type of weapon used or the location of a crimes — went from 23 tables in 2015 to 6 in 2016.

There were 15 tables of murder data in 2015, but in 2016 there were only a few tables offering expanded insights on homicides. The expanded homicide data from 2016 doesn’t include statistics on the relationship between victims and offenders; victims’ and offenders’ age, sex, race or ethnicity; or what weapons were used in different circumstances. Practically speaking, that means that researchers can no longer easily identify the number of children under the age of 18 murdered by firearm in a given year. Additionally, data tables used to identify the number of women murdered by their partners are similarly no longer available.

The removal of this expanded homicide information is not acknowledged in the report. Also, the FBI’s 2016 definition of expanded homicide data, which is identical to the one from 2015, says that the agency collects “supplementary homicide data that provide the age, sex, race, and ethnicity of the murder victim and offender; the type of weapon used; the relationship of the victim to the offender; and the circumstance surrounding the incident. Statistics gleaned from these supplemental data are provided in this section.” This suggests that murder circumstance data will be provided, though none is.

While the UCR says that the data no longer included in the report was available upon request, the FBI only provided a raw data file, which is more difficult to analyze — especially compared to easily accessible data tables — and does not always match the figures posted online in the UCR reports.

The FBI noted that in addition to its decision to streamline the report, UCR had launched a Crime Data Explorer, which aims to make crime data more user-interactive. But data contained in the explorer does not replicate what is missing from the 2016 UCR report, and it doesn’t allow users to view data for particular years, but rather aggregates trends over a minimum period of 10 years. The National Incident-Based Reporting System is another tool the FBI uses to provide more detailed information on crimes, but it too does not replicate what is missing from the 2016 UCR report and has a substantially lower participation rate from police departments across the country.

Richard Rosenfeld, former president of the American Society of Criminology and a professor at the University of Missouri, St. Louis, noticed that the 2016 report no longer had data for a trend area that he tracks — homicides related to the narcotic drug trade. “One could argue the Trump administration is interested in the opioid epidemic and might be interested in its criminal justice consequences,” he said.

“I simply don’t understand why they would omit any of the tables that they have included from years past.”

If you have any tips or insights into the changes to the 2016 Crime in the United States Report, please send them to clare.malone@fivethirtyeight.com.