During and after the Gulf War, people reported that they had been exposed to chemical warfare agents. To investigate these incidents and to determine if chemical weapons were used, the DOD developed a methodology for investigation and validation based on work done by the United Nations and the international community where the criteria include:
- A detailed written record of the conditions at the site.
- Physical evidence from the site such as weapons fragments, soil, water, vegetation or human/animal tissue samples.
- A record of the chain of custody during transportation of the evidence.
- Testimony of eyewitnesses.
- Multiple analyses.
- Review of the evidence by experts.
While the DOD methodology (Tab D) for investigating chemical incidents is based on these protocols, the passage of time since the Gulf War makes it difficult to obtain certain types of documentary evidence, and physical evidence was often not collected at the time of an event. Accordingly, our methodology is designed to provide a thorough, investigative process to define the circumstances of each incident and determine what happened. Alarms alone are not considered to be certain evidence of chemical agent presence, nor is a single individuals observation sufficient to validate a chemical agent presence.
By following our methodology and accumulating anecdotal, documentary, and physical evidence, and by interviewing eyewitnesses and key personnel, and analyzing the results, the investigator can assess the validity of the presence of chemical warfare agents on the battlefield. Because information from various sources may be contradictory, we have developed an assessment scale (Figure 1) ranging from "Definitely" to "Definitely Not" with intermediate assessments of "Likely," "Unlikely," and "Indeterminate." This assessment is tentative, based on facts available as of the date of the report publication; each case is reassessed over time based on new information and feedback.
Figure 1. Assessment of Chemical Warfare Agent Presence
The standard for making the assessment is based on common sense: do the available facts lead a reasonable person to conclude that chemical warfare agents were or were not present? When insufficient information is available, the assessment is "Indeterminate" until more evidence can be found.