Apportioning Culpability in Multiple Perpetrator Acts of Terrorism2

The Depravity Standard instrument was developed to operationalize depraved elements of crimes. It consists of 25 items that were derived using multiple sources of data, including case reviews, input from professionals, and over 40,000 survey respondents. This paper presents preliminary data on the use of the Depravity Standard in cases with multiple perpetrators, examining its efficacy in differentiating the culpability of co-conspirators in a terrorist act. The U.S. has been the site of three high-profile terrorist events with dual perpetrators:

the 1995 Oklahoma City bombing by ex-U.S. Military acquaintances Timothy McVeigh and Terry Nichols; the 2013 Boston Marathon bombing by brothers Tamerlan and Dzhokhar Tsarnaev; and the 2015 San Bernardino…