A whodunnit - Part 1
An exploration of probability through murder - a preface
I’m sure many of you are aware of the OJ Simpson case in the US in the 90s (the 1990s for anybody reading this 100 years from now). For those who are not, OJ was an American Football (shitty sport) player whose wife was murdered along with her friend. OJ, who admitted to beating his wife in the past, was tried for the case and found not guilty. There was one aspect of the trial which is quite interesting from the point of view of probability. Alan Dershowitz, the defense counsel, said that “Only one in a thousand abusive husbands eventually murder their wives.” The conclusion he drew from that was that being abusive should not count as substantial evidence in this trial. However, Alan Dershowitz, whether knowingly or not, was missing an essential part of the story. The part he was missing was that the wife was murdered. So, the significant probability is not the chance of an abusive husband murdering their wife but that an abusive husband of a murdered wife killed her. If we ask this question, the probability goes up by a significant amount. This article estimates it to be 97%. You often find that in situations like these, when dealing with probability, the hard part is asking the right question. Don’t be concerned if you don’t see the distinction between these two questions currently. The goal of this series is to make such differences clear.
This series will not deal with OJ Simpson - there is enough written about that case. Instead, it will be about a mother, Vilila and her son, Wrinje, reading about a murder in the newspapers. Given the publicly available information and what they know about the world, they try to figure out who did the murder.
Being a fundamentally lazy human being, there are times where I will make up statistics off the top of my head to avoid having to look things up. So, there will be a mixture of real statistics and fake ones. I will try to indicate when things are real and when they are not.
See you in Part 2, where we will begin the exploration. Make sure to sign up for email updates and share this with those you think may be interested.