Painting Bleak Portrait of Urban Crime, Trump Sends More Agents to Chicago and Other Cities

Still, Mr. Barr joined Mr. Trump in blaming politics for a recent rise in crime rates, although they remain far lower than what they were a generation ago. He denounced what he portrayed as the demonization of the police and calls to defund local law enforcement agencies.

“This rise is a direct result of the attack on the police forces,” Mr. Barr declared.

The additional agents will be reassigned from other tasks at Justice Department agencies like the F.B.I., the Drug Enforcement Administration, the United States Marshals Service, and the Bureau of Alcohol, Tobacco, Firearms and Explosives, as will law enforcement officials from the Department of Homeland Security, Mr. Barr said.

He said the agents would be part of the same effort announced several weeks ago for Kansas City, which the Justice Department is calling Operation Legend, after LeGend Taliferro, a 4-year-old boy who was killed there.

Mr. Barr also announced grants of about $3.5 million for Chicago to help compensate for overtime and other expenses incurred in supporting the federal task force and $3.6 million for Kansas City to hire additional police officers. Mr. Trump said that in all, $61 million in federal grants would go to hire more police officers in cities that are eventually included in the operation.

While there is nothing unusual about federal agents teaming up with local police on task forces to investigate gang violence or drug trafficking networks, the Trump administration’s recent efforts — pegged to Mr. Trump trying to make political hay of bashing Democratic elected officials, and coming against the backdrop of the disputed intervention in Portland — have strained federal and local relations.

The mayor of Kansas City, Quinton Lucas, a Democrat, has said he was caught by surprise when the Trump administration announced Operation Legend for his city, saying that he learned about it on Twitter. He said he supported receiving help in solving crimes but was worried that the federal agents may end up being political props.