Correction appended: April 15, 2014.
Law-enforcement officials announced on Monday that they had enough evidence to charge Frazier Glenn Cross for a hate crime in the shooting at a Jewish community center and senior living facility that left three people dead.
“We have unquestionably determined through the work of law enforcement that this was a hate crime,” Overland Park police chief John Douglass told the Associated Press. Cross, a former member of the Ku Klux Klan, was reportedly heard shouting “Heil Hitler” from the back of a police car while in custody.
Hate crimes, which are motivated by biases based on race, religion, sexual orientation, ethnicity/national origin and disability, have dropped in the U.S. in recent years. In 2012, there were 5,796 incidents, compared with 6,222 reports in 2011, according to the FBI. Racially motivated violations still make up nearly half of all hate crimes, followed by 20% that are tied to sexual orientation.
While violent crime in the U.S. has dropped as well, the decline in hate crimes hasn’t been as rapid and may be harder to combat, says Jack McDevitt, associate dean for research in the college of social science and humanities at Northeastern University. That’s because neighborhoods in the U.S. are only becoming more diverse, which means that locally and even personally perceived biases or injustices may become more glaring to certain individuals. “I fear [such hate crimes] will increase,” McDevitt says. “There are people out there who see increasing diversity as a threat, then they strike out.”
Contrary to what sociologists believed for years — that hate crimes are fueled by economic pressures as new groups received benefits or better jobs – the driving force may be something more basic to human nature: our tendency to feel threatened in the face of change. “One of the major sources of hate crime is what is perceived of as rapid in-migration of other groups into formerly racially, ethnically or religiously homogenous areas,” says Donald Green, a professor of political science at Columbia University, who has studied this connection extensively. “From the standpoint of a hate crime, the tipping point is the very first group that moves in.” As people feel threatened and believe they need to “defend” their neighborhood or way or life, that’s enough to prompt vandalism or violent crime, he says. In contrast, in issues involving housing regulations or schooling, about a quarter or a third of the population needs to change before a threat is perceived and acted upon.
Antiracial crimes committed by far-right extremists are more likely in communities with a denser Jewish population, according to a U.S. Extremist Crime Database study, led by Joshua Freilich of the John Jay College of Criminal Justice, Roberta Belli of United Nationals Department of Safety and Security, and Steven Chermak of Michigan State University. For example, hate crimes against Jewish communities are more common in states with higher Jewish populations; in New York, where they make up 9% of the state’s population, there were 248 such incidents in 2012, a nearly 30% increase from 2011. One reason, Freilich hypothesized in an email to TIME, is the possibility that “far-right racist leaders focused their efforts on counties where Jews were visible, and inspired their supporters residing in those counties to lash out and attack the far-right’s ideological enemies.”
Such patterns of scapegoating and blame may make hate crimes frustratingly difficult to curb downward, says McDevitt, and that means that tragedies like the shootings in Overland Park, Kans., may continue to percolate across the country.
Correction: The original version of this article misstated Steven Chermak’s institutional affiliation. He is affiliated with Michigan State University.