Durham, North Carolina - U.S. law enforcement agencies rank the threat of violence from anti-government  extremists higher than the threat from radicalized Muslims, according to a report released Thursday by the Triangle Center on Terrorism and Homeland Security (TCTHS).

The report, “Law Enforcement Assessment of the Violent Extremism Threat,” was based on survey research by Charles Kurzman, professor of sociology at the University of North Carolina at Chapel Hill, and David Schanzer, director of TCTHS and associate professor of the practice at Duke University’s Sanford School of Public Policy.

”The data show that we have two distinct, serious, ongoing terrorist threats in the United States,” Schanzer said. “Tragic incidents of violence, whether they be in Charleston or the Boston Marathon, tend to exaggerate the magnitude of the threat, but both will require consistent societal and law enforcement vigilance in the foreseeable future.”

The survey -- conducted by the center with the Police Executive Research Forum -- found that 74 percent of 382 law enforcement agencies rated anti-government extremism as one of the top three terrorist threats in their jurisdiction. By comparison, 39 percent listed extremism connected with Al Qaeda or like-minded terrorist organizations as a Top 3 terrorist threat.

Seven percent of the departments rated the threat from anti-government and other forms of extremism as severe, while 3 percent considered the threat from Muslim extremists severe.

Local agencies perceive violent extremism to be more of a threat nationally than within their own jurisdictions. Rural agencies report threats of all forms of violent extremism lower than agencies in mid-size and larger cities.

The data were collected in early 2014, before security agencies began noting increased activity and recruitment of Americans by the self-proclaimed Islamic State (ISIS). In follow-up telephone interviews, the officers did not modify their initial responses in light of ISIS threats within the United States.

Schanzer and Kurzman wrote about their findings in an op-ed published in The New York Times June 16, the day before the shooting of nine African-Americans in a church in Charleston, S.C. Their research has become part of the national dialogue in the aftermath of the crime.

“While public attention focuses primarily on violent extremism associated with Muslims, this horrible crime appears to be drawing public attention to other forms of violent extremism that law enforcement agencies have been concerned about for a while,” Kurzman said.

The report is the first issued from a larger project that also covers community-outreach programs by law enforcement agencies as a technique for countering terrorism.

The project is supported by the National Institute of Justice, Office of Justice Programs, U.S. Department of Justice (Award No. 2012-ZA-BX-0002). A full copy of the report is available here.