The National Consortium for the Study of Terrorism and Responses to Terrorism (START) has released two research briefs that delve into latest updates to the Profiles of Individual Radicalization in the United States (PIRUS) dataset.

The first research brief offers an analysis that “illustrates the important differences that exist across ideological groups and highlights recent trends in the data.” Some noteworthy take-aways:

1. 1. 1. From 2019-2021, 75% of the 20 most criminally active groups and movements came from the extremist far-right.
      2. Subjects inspired by the Islamic State of Iraq and the Levant (ISIL) remained active from 2019-2021; however, there was a sharp decline to 55 offenders from more than 100 offenders during 2016-2018.
      3. More than 70% of offenders who committed crimes since 2010 either acted alone or with a small number of isolated co-conspirators. 
      4. Lone offenders are 49% more likely to be classified as violent than subjects who have at least one co-offender.

The second research brief “provides an overview of the mass casualty crimes in PIRUS, including their frequency, links to ideological and sub-ideological groups, and a comparison of their perpetrators.” Some important data include:

1. 1. 1. From 1990-2021, 631 subjects collectively were involved in 439 events that are classified as mass casualty plots.
      2. 295 of the mass casualty plots linked to subjects in PIRUS were foiled by law enforcement.
      3. Locations with large populations and dense urban areas were most frequently targeted.
      4. White supremacists were responsible for 33% of all mass casualty plots and crimes in the data.

The PIRUS dataset can be explored more in-depth here.

For additional resources, view the HSDL In-Focus topics for Domestic (U.S.) Terrorism, Active Shooters, Hate and Antisemitism, the January 6th Capitol Attack, and more.