Amini died as a result of a heart attack or stroke (not induced by violence).
(71% probability)Question
How did Mahsa Amini die?
11 Dec, 2022Answer
Background
On 13 September 2022, a 22-year-old Iranian woman named Mahsa Amini, was detained by Iran’s Guidance Patrol (also known as “the morality police”) for violating Iran’s dress code. Two hours later she was hospitalized, and after three days in a coma, she was declared dead.
Her death sparked a wave of protests in Iran by those who believe she was murdered by the police, while the official investigation claims she died of natural causes. As no definitive evidence emerged thus far, a probabilistic analysis is needed.
Hypotheses Considered
Calculated Results
Calculated Results
1
71%
Amini died as a result of a heart attack or stroke (not induced by violence).
71%
2
15%
Amini was struck by the Guidance Patrol, leading to an unlikely nor intended outcome.
15%
3
14%
Amini was intentionally beaten to death by the Guidance Patrol, for example for religious reasons.
14%
Starting Point
Initial Probabilities
Name
Updated Likelihoods
To calculate the initial probabilities of the Murder and Involuntary Manslaughter hypotheses, we researched all deaths that occurred in the last 20 years while in the Guidance Patrol’s custody (in circumstances similar to Amini’s) and divided this number, by the number of people they detain.
For the Natural Causes hypothesis, we calculated the combined likelihood of a person in Amini’s age group dying due to her claimed causes of death (a stroke or heart attack).
While dying while in the Guidance Patrol’s custody is rare (we found only two cases that are somewhat similar to Amini's), dying at Amini's age from a stroke or heart attack is even rarer. This means the Natural Causes hypothesis is highly unlikely compared to the two competing hypotheses, before considering the specific evidence in this case.
Name
Updated Likelihoods
Evidence
Effect
Video of the incident
Name
Effect
Updated Likelihoods
The CCTV video documenting Amini from her arrival at the detention center up until her collapse depicts no violence and no indications of prior violence. Amini and everyone who exits the police van with her seems calm and acts normally.
As such, this evidence is extremely unlikely under the Murder hypothesis, somewhat unlikely under the Involuntary Manslaughter hypothesis, and to be expected under the Natural Causes hypothesis.
Name
Effect
Updated Likelihoods
Medical diagnosis
Name
Effect
Updated Likelihoods
There have been three main sources claiming to provide medical evidence or a diagnosis as to the cause of Amini's death: leaked medical tests that appeared in the media, pictures of Amini in the hospital, and an official diagnosis by Iran’s coroner.
We disregard these claimed tests as they are uncorroborated and originate from an unreliable source. Amini’s hospital pictures and the coroner report show no indication of violence and as such, reduce the likelihood of the Murder and Involuntary Manslaughter hypotheses.
Name
Effect
Updated Likelihoods
Testimonies
Name
Effect
Updated Likelihoods
Testimonies appearing in the media have mostly described Amini being beaten by the police, which supports the Murder and Involuntary Manslaughter Hypotheses. However, this effect is reduced as all of these testimonies are uncorroborated, hearsay testimonies, mediated either by media organizations funded by countries aiming for regime change in Iran or by Amini’s family, who are more likely to provide such information whether true or false. At least part of Amini’s family also has a significant bias against Iran’s government and is active in a political and armed conflict against it, with the hope that "these protests will continue and it will end with the fall of the Islamic Republic". On top of this, some testimonies contain internal contradictions while others are contradicted by the CCTV footage.
A few of the testimonies do carry more significant weight: Amini’s father claimed she did not have brain surgery (contrary to official claims) and that he saw blood on her body. These claims further support the Murder and Involuntary Manslaughter hypotheses while one testimony significantly supports the Natural Causes hypothesis: Amini’s brother received the diagnosis that his sister suffered a stroke and a heart attack within 17 minutes of her collapse. This is unlikely to be sufficient time to establish a conspiracy to hide her true cause of death and thus was likely a truthful diagnosis.
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Effect
Updated Likelihoods
Discussion