What is Considered a Suicide Attack?
CPOST defines a suicide attack as an attack in which an attacker kills himself or herself in a deliberate attempt to kill others. CPOST includes only suicide attacks perpetrated by non-state actors; attacks authorized by national governments are not included. The classic example is a suicide bomber detonating an explosive vest (a “belt bomb”) or explosives in a vehicle the bomber is driving (a “suicide car bomb”). The critical criteria is suicide: the attacker must kill him or herself, even if no one but the attacker dies in the attack. The CPOST-SAD does not include (1) failed suicide attacks where explosives do not detonate or are detonated by someone other than the attacker (e.g. the explosives were set off by a gunshot from police); or (2) “suicide missions,” where the attacker expects to be killed while killing others, but does not directly kill himself or herself.
Which attacks are included in the database?
To be included in the database as confirmed suicide attack, an attack must meet two criteria:
At least one attacker must kill him or herself to kill others.
The attack must be verified by at least two independent sources.
CPOST separates all potential suicide attacks into two categories: confirmed suicide attacks and possible attacks. To be counted as a confirmed suicide attack, the attack must be reported by two independent sources. These do not include two sources that gain information from the same newswires. For instance, if two sources both use a Reuters newswire as the basis of their report, the sources will not be considered independent. Group claims also serve as an independent source for attacks and generally provide insight into information surrounding individual attackers.
CPOST also tracks of possible suicide attacks it identifies. Possible attacks fall into three categories:
Attacks with only one source
Attacks that only appear in group claims and not in any other sources
Attacks where news sources conflict as to whether the attack was a suicide or not.
CPOST collects possible suicide attacks because information may become available in the future to confirm the attack. CPOST periodically reviews possible attacks. If, upon review, new information confirms a possible attack as suicide, the attack is added to the database. The opposite is also true: if new evidence reveals that an attack no longer meets CPOST’s criteria for inclusion, it is removed.
Failed suicide attacks – attacks in which the attack does not kill him or herself – and suicide missions – attacks where the attacker dies, but not by his or her own hand – are not collected.
Double verification of the attack is crucial: it greatly reduces bias from any single source to ensure the most accurate record of suicide attacks. Accordingly, users of CPOST data can have high confidence that the attacks in the Suicide Attack Database have actually occurred.
What are the sources of potential bias?
Data on suicide attacks comes from a variety of possible sources, including governments, the media, and the groups that perpetrate suicide attacks themselves. Each has its own potential for bias. For example, governments may have an incentive to over-report attacks as suicide to mobilize support for costly counterinsurgency measures, or to under-report such attacks to create a false impression of competence and security. Groups routinely over-report suicide attacks and the casualties they inflict to mobilize support. Media reports might be based on preliminary evidence or rumors. Requiring a minimum of two sources increases our confidence that the suicide attacks in the Suicide Attack Database is accurate in addition to comprehensive.
Must attacks be considered “terrorism” to be included in our database?
Suicide attacks are often associated with “terrorism” in the media, policy, and academia. The boundaries of what counts as “terrorism,” however, is notoriously difficult to define. CPOST is agnostic on whether a given suicide attack qualifies as “terrorist” or might better be described as some other form of violence (for example, a guerilla attack or an attack with no obvious political motivation). Beyond the non-state qualification, any attack meeting the definition of suicide attack and our two-source requirement is included.