America’s increase in homicides over the past two years may be attributable to the concurrent opioid crisis, according to a new report from the DOJ-affiliated National Institute for Justice, which also suggests increased public antagonism towards the police has also played some role.
U.S. homicide rates have spiked over the past two years, rising 11.4 percent from 2014 to 2015 and 8.2 percent from 2015 to 2016. Violent crime rose in 38 out of 50 states, with a particularly pronounced spike in America’s big cities. In cities with more than 250,000 residents, homicides rose by 15.2 percent between 2014 and 2015, and by 10.8 percent between 2015 and 2016.
Notably, the increases took place across the country, and in different cities in different years. "Cleveland, Nashville, Denver, Baltimore, and Oklahoma City had the five largest percentage increases in 2015. Austin, Chicago, San Antonio, San Jose, and Louisville topped the list in 2016," the report notes.
The report investigated two "plausible candidates" for the increase: the heroin and synthetic opioid epidemic; and the publicizing of incidents of police violence against black Americans, leading to "ensuing protests and civil unrest in many cities," the so-called Ferguson effect.
The exploding opioid epidemic, recently designated a public health crisis by President Donald Trump, is predictably associated with an increase in violent crime, as a greater demand for drugs fuels drug-traffickers' violence. The report notes that the proportion of arrests for heroin and cocaine (which are aggregated) rose between 2014 and 2015, after falling for the preceding three years.
"A speculative but plausible reason for the increased police attention to heroin in recent years is growing violence in and around illicit drug markets," the report reads.
This is further supported by analysis that concludes drug-related homicides accounted for 22 percent of the total homicide increase between 2014 and 2015. (This number, it should be noted, is imprecise: 39.9 percent of homicides in 2015 were not attributed a cause in official data.) The bump in opioid-related homicides also helps explain the increase in homicide among the white population, who are the primary users of opioids by ethnicity.
The analysis surrounding the Ferguson effect is more mixed. The cause of the effect, as explained by Heather Mac Donald and others, is that increased media focus on racialized police violence leads to increased hostility toward the police by both politicians and the general public. This tension leads to police curbing their own proactive policing, which in turn leads to an increase in the crime rate.
According to data reviewed by the report, police do feel more pressure from their communities: A 2017 Pew survey of some 8,000 officers in large departments found that 90 percent of officers were more concerned about their safety than they had been. Seventy-five percent said that fellow officers were less willing to use force, and that tensions had increased with black community members; more than 70 percent said officers were less willing to stop and question people.
The survey, the report contends, is a "useful but incomplete indicator of police behavior." Pew's research is then supplmented by by examining the ratio of arrests to violent offenses, which declined "modestly" between 2014 and 2015. The arrest clearance rate also fell modestly, or remained flat, over 2010 to 2015; the arrest rate for minor crimes fell over the same period.
But, the report points out, these declines in arrests preceded protests in Ferguson, Mo. and other cities—in other words, something else was causing arrest rates to drop already, at least in part.
"It is possible that the timing of changes in other enforcement indicators, such as pedestrian or vehicle stops, is more consistent with a Ferguson effect," the report notes. "A reasonable conclusion from the available data, however, is that the case for linking the homicide rise to de-policing remains open."
The paper also examines another version of the Ferguson effect, by which increased alienation from the police causes predominantly black communities to disregard them, leading to a problem of police legitimacy. The paper demonstrates that a decline in legitimacy can have a criminogenic effect, and that black Americans’ opinions of the police did decline following police killings in Ferguson and elsewhere in 2014 and 2015. However, the report cautions against ascribing too much significance to these data, especially given the lack of more local-level evidence.
"The relatively modest post-Ferguson decrease in public confidence in the police cannot, by itself, explain homicide increases of 25 percent or more in big cities during the past few years," the report concludes.
While the report is restricted to analyzing the impact of the opioid crisis and the Ferguson effect, it does not claim that these exhaust the causes of the homicide spike. Rather, they should be understood as more severe short term factors, complementing longer-run or unseen short-run trends.
Indeed, the paper's authors conclude by suggesting their research is mostly preliminary, recommending more finely tuned case studies and a better identification of key indicators tied to the ebb and flow of homicide rates.
The National Institute for Justice is the Department of Justice's research arm, and "is dedicated to improving knowledge and understanding of crime and justice issues through science."