Video's Role in the Investigative Process

All About Evidence: Ghouta to Bhopal


The goal of collecting evidence is to accurately recreate the story of what happened during an incident where human rights are violated, so that you, along with investigators, lawyers, judges, and, ultimately, the world, can bring perpetrators to justice, free the wrongly accused or secure solutions to economic, social and cultural rights violations.

Sometimes, the factually correct version of the story may not be the story we hoped to tell. As human rights advocates, we must be prepared to discover the truth, even if we find that the truth is not aligned with what we initially believed happened.


A group of human rights defenders who were well informed about the alleged chemical weapons attacks on the suburbs of Ghouta, Syria, on August 21, 2013, were asked to watch video clips of the aftermath of the chemical weapons attack and compare those clips to the aftermath of an industrial disaster that occurred on December 3, 1984, in Bhopal, India, when a cloud of toxic gas escaped from Union Carbide’s pesticide plant, killing thousands. The viewers were, for the most part, unfamiliar with the incident in India prior to watching the video.

This 2.5 minute video combines footage from Ghouta and Bhopal. It first shows victims from Ghouta suffering from constricted breathing and involuntary muscle spasms, frothing at the mouth, seeping fluid from their noses and eyes, and dying. It then shows people from Bhopal suffering very similar symptoms.

WARNING: This clip contains graphic footage that may not be appropriate for all viewers.

Ghouta, Syria

Ghouta, Syria

Bhopal, India

Bhopal, India

The human rights defenders were then asked, “What does this video footage offer proof of?” In short, they answered that the video footage was proof of chemical weapons attacks in Syria and likely some sort of poisoning in India. They were right about India, but wrong about Syria.

While the answer regarding Syria was wrong, it is understandable. The human rights defenders knew additional details about the incident in Syria from the expansive media coverage of the alleged chemical weapons attacks and, in turn, made assumptions about what the video proved.

Upon discussion, however, they agreed that the videos themselves did not prove a chemical weapon attack at all. The video clips only indicate that hundreds of people in Ghouta and Bhopal suffered from some sort of massive airborne poisoning that seemed to affect everyone — from the very young to the very old. The images do not prove that a poisoning happened. The images also do not tell us how the probable poisonings happened, why they happened, or who might be responsible. While the videos don’t provide the answers to these critical questions, they do offer up invaluable leads for determining what happened in both situations.


  1. When it comes to analyzing video as evidence, we must set aside our outside knowledge and assumptions and think critically about what a video clip actually indicates and proves.


As we saw in Part I of the Ghouta Field Note, while the videos from Ghouta, Syria, and Bhopal, India, did not prove a crime had been committed, the videos alerted the global community hat something was very wrong. In both of these cases, videos served as what is referred to as lead evidence. The world learned that a crime may have been committed when it witnessed, through multiple videos, a large number of people suffering from symptoms of apparent poisoning — constricted breathing and involuntary muscle spasms, frothing at the mouth, fluid seeping from their noses and eyes, and death. For Ghouta, the videos compelled the UN to send in a team of investigators to determine what happened.

Once on site, the UN investigators collected and tested blood and urine samples from victims. The samples tested positive for Sarin gas. These samples provided definitive evidence of exposure to Sarin. Lawyers refer to this as prima facie evidence, as it establishes a key fact — exposure to the gas. It still does not, however, establish whether the poisoning was purposeful or not.


To strengthen the conclusion that civilians were exposed to a nerve agent, the videos were considered alongside clinical medical examinations showing typical symptoms of exposure to a nerve agent, as well as testimony from survivors, nurses, and doctors, detailing the symptoms they saw and experienced after the shelling. The videos, medical exams, and witness testimony are referred to as corroborative evidence, because they back up the results of the blood and urine tests. Together, these sources of evidence confirm exposure to Sarin gas, but again, the evidence does not yet establish whether the poisoning was purposeful nor provide any insight into the source of the gas.

The UN investigators also completed a site visit to what was believed to be the impact zone of the rockets carrying the poison. Technical and military analysis of the impact zone, combined with subsequent laboratory tests, confirmed that the rockets and rocket fragments contained Sarin gas. This analysis of the impact zone and the weapons provided what is called inferential evidence because the results allowed investigators to infer that the attack was purposeful, since it would be unlikely for surface-to-surface missiles loaded with Sarin gas to launch themselves.

Witness testimony confirming that shelling took place immediately before the victims started showing symptoms of poisoning further corroborates the conclusion that surface-to-surface rockets were used to deliver the gas.

The next step is to prove responsibility by uncovering evidence that links the perpetrator to the crime. This is called linkage evidence. Without linking the crime to a person, we cannot secure accountability. In this case, initial investigations suggested that the type of rockets and launchers used in the attacks on Ghouta were weapon systems known and documented to be in the possession of, and used only by, Syrian government armed forces. If proven, this fact will likely serve as linkage evidence connecting the attack to the Syrian regime. For criminal accountability, it will be necessary to go a step further and identify particular individuals who ordered, carried out, assisted, or tolerated the attack.


  1. First, investigators, analysts, and lawyers prove their cases by piecing together di erent sources of evidence for different purposes, allowing them to tell the full story of what happened. In this case, the UN investigators were able to conclude, on the basis of clear and convincing evidence, that chemical weapons were used against civilians. They began with the videos and then used witness testimony, medical exams, medical lab results, weapons analysis, and technical assessments to con rm that the attack was purposeful.
  2. Second, as a frontline documenter, remember that footage documenting the commission of crimes is valuable. But your e orts to capture linkage and notice evidence will likely prove to be of greater importance for long-term justice and accountability. With only 7.5 hours on the ground, combined with follow-up analysis, the UN investigation team was able to prove a crime — a chemical weapons attack against civilians — was committed, by clear and convincing evidence. This was the easy part. Proving who did it and how is much harder, and at the time of writing still had not been accomplished.


Investigation has sometimes been likened to assembling a jigsaw puzzle and each piece of evidence to an individual piece of t he puzzle. However, unlike t he puzzle assembler, t he investigator cannot look on t he cover of the box to see what the completed puzzle will look like. The investigator must carefully collect the “pieces” of t he puzzle from a variety of sources and t hen assemble t hem wit h logic and common sense in order to see that entire picture. Although a partial picture may develop as more and more pieces are added, it is not until the final piece is placed that the investigator can clearly see the entire truth.


This analogy also demonstrates t he relationship between evidence and speculation. Assume t hat t he person assembling the puzzle, like the investigator, does not know what the completed puzzle will look like. It is impossible for t hat person to look at any one piece and know what t he entire picture is. If t hat person only has ten percent of the puzzle’s pieces and assembles them as best he or she can, it is probably still impossible to accurately guess what the picture looks like. The person may speculate, but with ninety percent of the puzzle missing, it is very likely that he or she will be wrong. The more pieces the assembler finds, the less he or she will have to speculate about the picture. Similarly, in an investigation, the investigator must gather all the evidence and assemble it with common sense before a clear picture of what happened is revealed. While an incorrect guess about what a puzzle will look like is of no consequence, the gravity of a human rights investigation requires that an investigator never speculate or guess about the ultimate facts of a case. The investigator must carefully and methodically gather as much evidence as possible in hopes that it will be sufficient to determine, without speculation, what happened.

Excerpt from The Handbook of Human Rights Investigations by Dermot Groome

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