By Michael A. Jensen and Elena Akers

Recent mass casualty attacks in the United States have renewed a long-standing debate over the need for novel legislation to effectively prosecute domestic terrorism. Those who advocate for a new terrorism law argue that deficiencies in the US legal code present challenges to prosecuting domestic extremists, leading to unwarranted sentencing disparities in international and domestic terrorism cases. Critics of the proposal for a domestic terrorism law counter that the US legal code is sufficiently flexible for the courts to punish domestic extremists to the same extent as their international counterparts. Neither side, however, has produced an empirical assessment to support their claims. In this article, we address this research gap by analysing data on 344 US federal terrorism cases that were initiated between 2014 and 2019. We find that significant disparities are endemic to US federal terrorism prosecutions for three types of sentencing outcomes: length of incarceration; time spent on supervision upon release from prison; and the use of restrictive monitoring conditions. International terrorism defendants are more likely than domestic extremists to receive severe penalties for all three sentencing decisions even when controlling for criminal severity. Sentencing disparities in US federal terrorism cases are especially large when domestic extremists are prosecuted using common criminal charges, like weapons violations. We conclude with a discussion of what these findings mean for promoting judicial fairness in US terrorism prosecutions.

Perspectives on Terrorism Volume XVIII, Issue 1 March 2024

Michael Wolfowicz, Gian Maria Campedelli, Amber Seaward and Paul Gill

While countries differ significantly in how they handle terrorism, in the west, criminal justice systems tend to treat terrorism similar to other crime, with police, prosecutors, judges and courts, and penal systems carrying out similar functions of investigations, apprehension, charging, convicting, and overseeing punishments respectively. While there is a robust literature on deterrent effects for crime, there is a dearth of research when it comes to terrorism. This despite evidence of significant overlaps between crime and terrorism. We address this gap in the literature with a unique dataset covering terrorism offending, arrests, charges, convictions, and sentencing over 16 years in 28 EU-member states. Applying a dynamic panel data model, we find that the probability of apprehension and punishment has an inverse relationship with terrorism offending. Conversely, the rate of charged individuals is associated with a small increase in the terrorism offending rate. The results for sentence length are less clear, with either negligible, or small iatrogenic effects. The results demonstrate that the overlap between crime and terrorism may extend to general deterrence. These findings should be informative for both the research agenda and policy discussion.

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