INVESTIGATORY STRATEGIES USED IN FOILED TERRORIST PLOTS IN U.S.
SLT law enforcement agencies, fundamentally changing how information is shared both
horizontally and vertically between agencies (Carter, Carter, & Chermak, 2013; Carter, Carter,
Chermak, & McGarrell, 2017). In response, many SLT law enforcement agencies have since
expanded their intelligence gathering practices, and there have been fundamental changes in the
national, state, and local information sharing infrastructure.
American SLT law enforcement agencies remain concerned about affiliates of both far-
right extremism and jihadism (Chermak, Freilich, & Simone, 2010; Freilich, Chermak, &
Simone, 2009; Levitt, 2017). Findings from the U.S. Extremist Crime Database (ECDB) reveal
that supporters of Al Qaeda and affiliated movements committed over 45 homicide incidents that
claimed over 3,000 lives since 1990. Far-right terrorists have committed over 190 ideologically
motivated homicide events claiming over 450 lives in this same period (Freilich et al., 2014).
Strom et. al (2017), who studied terrorism plots foiled between 1995 and 2012, conclude that
both jihadists and far-rightists accounted for the majority of actors planning to attack the U.S.
and that each ideological movement engaged in a similar number of the identified plots.
Importantly, though, scholars have yet to investigate whether distinct investigatory
strategies are utilized for intercepting terrorists who are driven by different ideologies. Extreme
far-rightists and jihadists have attacked, or have planned to attack, a diverse list of targets using
various strategies (Drake, 1998; Kaplan, 2012; Legault & Hendrickson, 2009; Lemanski &
Wilson, 2016; Gruenewald, et al., 2016). While some attacks are carried out by multiple
offenders associated with formal groups, far-right and jihadi lone actor events are also of major
concern and may be on the rise in the U.S. (Gruenewald, Chermak, & Freilich, 2013; Michael,
2012; Pantucci, 2013; Spaaij, 2010; Strom et. al, 2017). Law enforcement must be concerned
about both international and homegrown threats, including "foreign fighters" who travel abroad