Apparent intended lethality: Toward a model of intent to harm in terrorist bomb attacks

This article sets out the concept of Apparent Intended Lethality (AIL) with respect to terrorist bomb attacks and explores its measurement through objective behavioral indices. AIL is assessed for 120 bomb attacks carried out by animal rights and anti-abortion extremists in the United States. A wide range of AIL is observed, ranging from hoax attacks to highly lethal attacks. Multidimensional Scalogram Analysis (MSA) reveals that single-issue terrorist bombers' intended lethality can be modeled according to three independent dimensions: device strategy, targeting, and pre-event warnings. This model can be used to measure AIL for an individual terrorist attack or an entire terrorist campaign, and can identify cumulative and compensatory lethality strategies. Many have noted the difficulty of assessing terrorist motivations; AIL provides an empirically based assessment of a key facet of terrorist intentions.