Operation Cross Country XI focused on a single goal: taking out "pimps" who run human trafficking rings, the FBI said.
Google and Twitter executives are also expected to testify before the House and Senate intelligence committees on Nov. 1.
Around 500 law enforcement officers will be on hand when controversial white nationalist figure Richard Spencer speaks Thursday at the University of Florida.
The Harford County, Maryland, sheriff's office said a gunman who killed three co-workers and wounded three others in two states has been apprehended.
Anthony Allen Shore, the so-called Tourniquet Killer, was convicted of murdering one young woman and allegedly confessed to three other slayings.