Statistics on trial

The understanding of statistics in the legal context can be a difficult task for the uninitiated. History has demonstrated numerous examples where basic errors have been made when attempting to draw conclusions from probabilities in which an incorrect application of the principles is evident. As probability is often misunderstood by most members of the public, it is not
surprising that it also poses a real challenge to legal practitioners. This has led to erroneous conclusions “based on the evidence” that have become known as a variety of “fallacies”, including those of both the prosecutor and defence. It is essential that lawyers can correctly understand and interpret the statistical information provided by witnesses, expert or otherwise. This article provides a step in that direction by examining four high profile cases.