But the real kerfuffle came Friday, when the Justice Department sent letters to nine “sanctuary cities”—Sacramento, Chicago, New Orleans, Philadelphia, Las Vegas, Miami, Milwaukee, San Francisco, and New York City—warning about a loss of federal funds if they refuse to allow local law-enforcement agencies to provide federal immigration officials with the immigration statuses of those held in their custody. The move itself was widely expected, but the Justice Department announced the letters with stark, factually dubious assertions about some of the cities in question.

“Additionally, many of these jurisdictions are also crumbling under the weight of illegal immigration and violent crime,” the department’s statement asserted. “The number of murders in Chicago has skyrocketed, rising more than 50 percent from the 2015 levels. New York City continues to see gang murder after gang murder, the predictable consequence of the city’s ‘soft on crime’ stance.”

This statement fits in with a broader Trump administration effort to blame illegal immigration for what it describes as a growing crime wave, an unproven assertion at best. While the department correctly noted Chicago’s rising homicide rate—a problem frequently invoked by Trump to bolster his “tough on crime” stance—it then implicitly linked the rise in murders to illegal immigrants. That connection doesn’t seem to be supported by the available evidence: An analysis by the University of Chicago Crime Labs earlier this year couldn’t find a single definitive cause for the increase in gun violence, stumping researchers.

Friday’s statement also took aim at the Santa Cruz Police Department in California, albeit not by name. “And just several weeks ago in California’s Bay Area, after a raid captured 11 MS-13 members on charges including murder, extortion, and drug trafficking, city officials seemed more concerned with reassuring illegal immigrants that the raid was unrelated to immigration than with warning other MS-13 members that they were next,” the statement read.

That’s an apparent reference to a series of 12 raids targeting the gang in California’s Santa Clara County in February. Both the Santa Clara Police Department and the Department of Homeland Security carried it out, reportedly raising fears of a massive Immigration and Customs Enforcement raid among the city’s residents. “We want to make it very clear that these were not immigration-related arrests,” said Deputy Chief Dan Flippo told The Mercury News at the time. “We recognize the timing is unfortunate, but this is a federal criminal case that was five years in the making and has nothing to do with immigration.”

The Justice Department’s description of New York City was even more egregious. The city’s crime rate is at its lowest levels in a generation. Murders are down by 10 percent in the first quarter of 2017 compared with the previous year. And New York City Police Department officials partly attributed 2016’s decline in shootings and homicides to a reduction in gang-related violence.