FBI Director James Comey made headlines this week when he suggested police are hanging back because they fear being recorded while making arrests—and that this may be the reason violent crime is on the rise.
After several years during which police killings of minorities were regularly recorded by bystanders, Comey concluded that officers decided to deal with the resulting popular outrage by simply retreating.
“The numbers are not only going up, they're continuing to go up faster than they were going up last year,” Comey said.
Critics, however, quickly pointed out that recent upticks in crime are being compared with historic lows. Fordham Law School professor John Pfaff noted on Thursday that percentage changes can be misleading:
To illustrate, here's a chart of the number of homicides in the U.S. from 1960 to 2014. (The Federal Bureau of Investigation has compiled only preliminary numbers for the first half of 2015.)
In 2014 there were 53 more murders than the year before, but overall, the decline that began in the 1990s hasn't reversed. In the current decade, about 10,000 fewer murders have occurred each year than when crime rates peaked in the 1990s. That has happened as the U.S. population has increased.
Here's the same data as the chart above, expressed as the annual percentage change in murders:
There's a lot more up and down, along with several periods in which the number of homicides increased. Indeed, homicides increased slightly each year from 2000 to 2003 and again in 2005 and 2006. Overall, though, the level has remained much lower than during earlier peaks, and no one much remembers any great crime wave of the early 2000s.
"It’s important to understand just how far murders have fallen since 1990," Pfaff said. Gallup polls year after year find that people think crime is increasing, regardless of whether it is.
Comey said conversations with police leaders suggested officers on patrol may be "less likely to do the marginal additional policing [that] suppresses crime," according to a transcript provided by the FBI. "I don't know for sure whether that's an answer," he said.
He acknowledged that the rise may be from historic low crime rates, but said the increase was still troubling. "How does that make any of us feel any better?" he said. "A whole lot of more people are dying this year, than last year. Last year, than the year before. I don't why for sure."
Homicide trends also vary from place to place in America. In Chicago, one of the cities Comey singled out, the city recorded 196 murders through May 8, according to the city’s police statistics (PDF). This compares with 126 murders in the same period last year. While that's a 56 percent increase, again, the percentage seems large because the base is low, compared to historic peaks. In 1991, Chicago had more than 900 homicides.
That doesn't mean the numbers don't warrant attention. But they also require context. "Do we sort of ignore this? No. But we shouldn’t be racing into [saying], 'Oh my God, the crime drop is finally coming to an end,'" Pfaff said.
As for Comey's suggestion that the numbers reflect changes in policing because of backlash to police shootings or fear of being caught on video, it's too early to say. Scholars still debate the precise factors that contributed to the 1990s crime drop, after all. "Even if this is a sign of a trend, which we can’t say yet, understanding what’s causing that is probably years away," Pfaff said.