At first glance, the number seems like an error — as if an FBI statistician had accidentally transposed some digits in the bureau's annual report on crime released earlier this week.

Alas, anyone who has been paying attention to violence in Chicago knows the FBI didn't make a mistake — the shocking number is accurate. There really were 765 murders in Chicago in 2016. Chicago's annual murder total jumped 86% in the space of two years, evoking memories of the early 1990s crack wars when annual homicide totals regularly approached 1,000, reports the Daily Caller.

Chicago's wave of killing wasn't an aberration, nationally speaking. Six other major U.S. cities experienced a surge in murders in at least one year between 2014 and 2016.

Some criminal justice experts say there is a causal link between the unrest and the two-year rise in homicides nationwide. Heather MacDonald, a fellow at the Manhattan Institute, has dubbed the phenomenon the "Ferguson Effect," in reference to a rise in violent crime that followed the shooting of Michael Brown by Ferguson, MO, police officer Darren Wilson in 2014.

As McDonald sees it, agitation by groups such as Black Lives Matter, encouraged by slanted media coverage, has led to a retrenchment among big-city police forces. Street cops are so worried about being vilified by city leaders and the press that they are avoiding contact with the criminal element, she says.

"Cops are backing off of proactive policing in high-crime minority neighborhoods, and criminals are becoming emboldened," MacDonald wrote in a Sept. 25 piece for City Journal. "Having been told incessantly by politicians, the media, and Black Lives Matter activists that they are bigoted for getting out of their cars and questioning someone loitering on a known drug corner at 2 a.m., many officers are instead just driving by."

Another year's worth of FBI data adds weight to MacDonald's argument. Killings have spiked in several cities that experienced rioting or significant protest against the police.