The Department of Justice this week is sending a strong message to American cities: if you can't stop crime, federal agents may be on the way.

On Wednesday, Attorney General William Barr announced the launch of "Operation Legend" — named after a 4-year-old boy, LeGend Taliferrom, who was shot and killed while he was sleeping in Kansas City last month.

Kansas City is one of several American cities dealing with an uptick in crime. According to the Department of Justice, violent crime is up 40% since last year, with at least 100 murders so far this year.

The New York Times recently reported the top 25 largest American cities had seen a 16% increase in murders in recent months.

What is "Operation Legend?"

The mission will send around 100 FBI, ATF and DEA agents, as well as some U.S. Marshals, to Kansas City to aid in crime prevention.

Agents are not expected to assume command of active investigations but rather serve as a deterrent to violent crime.

"Operation Legend will combine federal and local resources to combat the disturbing uptick in violence by surging federal agents and other federal assets into cities like Kansas City, a city currently experiencing its worst homicide rate in its history," Barr said in a statement.

Kansas City will not likely be the last place federal agents go. The release hinted Kansas City was just the "beginning" of Operation Legend.