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A new report by a professor at UNC-Chapel Hill documents the low number of Muslim-Americans associated with violent extremism in 2019 has been issued by the Triangle Center on Terrorism and Homeland Security at Duke's Sanford School. In addition, the report presents original data on the lengthening period between radicalization and attempts at violence, allaying concerns voiced by counterterrorism officials about a quickening pace of “flash” to “bang.”

In 2019, 24 Muslim-Americans were arrested for involvement with plots of violent extremism in 2019, as compared with a peak of 88 arrests or attacks in 2015.  These arrests resulted in no fatalities. 

  • 12 of the 24 suspects were arrested for supporting terrorism abroad
  • Of the 12 suspects involved in domestic activities, 10 were arrested prior to engaging in violence
  • The 2 other suspects caused no injuries

Muslim-American extremists have caused 141 deaths in the 18 years since September 11, 2001. Over the same period, there have been more than 290,000 murders in the United States, and 254 lives were lost in mass shootings in 2019 alone, none by Muslim-American extremists. 

Data from federal prosecutions of Muslims inspired by ISIS from 2013-19 show that most cases had a lag time of more than a year between initial expressions of support for violent extremism and acts of violent extremism.   This lag time (“flash to bang”) has increased in recent years.

“This evidence suggests that radicalization rarely leads to violence overnight,” said Charles Kurzman, a professor of sociology at UNC-Chapel Hill and author of the report. “Counterterrorism officials have worried for years that flash-to-bang timelines were getting shorter, but the trend has actually been in the other direction.”

The report is the tenth in a series published annually since 2010 by the Triangle Center on Terrorism and Homeland Security.  The series offers systematic evidence on the pressing issue of terrorism. Data from past reports has been cited in congressional testimony, White House policy documents, judicial proceedings, national and international media, and scholarly work on the subject.

David Schanzer, director of the Triangle Center on Terrorism and Homeland Security, said, “A decade of data-collection and analysis has clearly established that the threat of homegrown violent extremism by Muslim-Americans remains to be of concern, but it is a low-volume, manageable threat.”

The full report is available at The data on which the report is based can be accessed at