Baye’s Theorem in the Justice System
In many courtrooms across the world, Baye’s Theorem is used to make informed decisions given incomplete evidence. This is both to make a more mathematical argument for the probability of guilt, and also to reduce logical fallacies make my jurors and legal officials, such as the prosecutor’s fallacy, where people often confuse the odds associated with a piece of evidence with the odds that a person is guilty. Baye’s theorem is just one of many statistical methods used to make legal rulings.
However, in a court of appeals, in a recent case regarding a murder trial, Baye’s theorem was used to make a decision, using evidence of a certain type of shoe print, compared to the number of those shoes out in the world. Due to uncertain numbers, this resulted in the sitting judge throwing the argument out. This would not be such a large issue if not for the further ruling, where the judge refused to accept statistical arguments with “shaky evidence.” This ruling threatens the ability of many mathematical tools for making informed legal decisions, and supporting the legal system overall.
Many mathematicians, such as Colin Aitken, professor of forensic statistics at the University of Edinburgh, urge against this decision. As the real world is not a perfect system, there will always be uncertainty and doubt in calculations made. However, these calculations, like those using Baye’s rule, still provide a valid response, and should be considered in legal arguments. Without these tools, many cases may potentially suffer, and suffer from both inefficiencies, and incorrect results made from those who are uninformed.
https://www.theguardian.com/law/2011/oct/02/formula-justice-bayes-theorem-miscarriage