The Reality Reports

People often judge a rule while knowing how it will affect them. A homeowner may view a tax differently from a renter. A healthy person may give less thought to medical access than someone with a serious illness. The philosopher John Rawls proposed a way to step outside these personal interests. His thought experiment asks people to design society without knowing the position they will occupy within it.

Television often shows a fingerprint entering a computer and producing one certain name seconds later. Real examinations are more careful. A print recovered from an object may be incomplete, smeared, stretched, or covered by other marks. Fingerprint evidence can be valuable, but it must be collected, compared, and explained properly. Understanding the process also shows why a possible match is one part of an investigation rather than automatic proof of a crime.