More than 20 major cities, including Chicago, Dallas, Las Vegas and Los Angeles, have seen large increases in murders in recent months, a spike that the director of the F.B.I. linked to less aggressive policing stemming from a “viral video effect.”
The new data released Friday showed clashing trend lines across the country, with many cities seeing a sharp increase in murders while rates in others — including New York and Miami — were down significantly from last year.
After receiving an advance look at the data, the F.B.I. director, James B. Comey Jr., expressed alarm Wednesday about the spike in murders in some major cities. Reigniting the debate over a “Ferguson effect,” he told reporters that he believed the trend could be linked to a “viral video effect” because officers were being less aggressive for fear of ending up on videos....
