Well then, if over 60% of fingerprints have the same pattern, how can they all be different? That is because fingerprints are examined using two different sets of criteria. One way of looking at fingerprints is using their "Class Characteristics". These are general features about the fingerprints, which apply to all fingerprints of that type ("Loop" is a class characteristic). For instance, to say that a car is a "Four-Door Sedan" is to talk about a 英语论文网 【http://www.51lunwen.org】Class Characteristic of that car. No one would suggest that all four-door sedans are exactly alike. If however, you were to say that the car had a New York State license plate number of X3D4R5, then that is what's called an "Individual Characteristic". No two cars have a New York plate number of X3D 4R5. So fingerprints are identified to a particular person using their individual characteristics, not their class characteristics. If you look very closely at a fingerprint, you will notice that it is made up of ridges on your skin. These ridges aren't always continuous; they stop, split into two, form little pockets (called "lakes") and even appear to cross each other at times. It's these individual features that are different between one fingerprint and the next. By examining and counting these individual features, a fingerprint expert can come to some opinion about whether a particular person made a particular fingerprint. If he or she finds characteristics that don't match, and can't be explained due to pressure distortion or other common problems, then they are obliged to state that the fingerprint did not come from that person. If they find a sufficient number of similarities however, and there are no unexplainable differences, then they may give the investigators and the court their expert opinion that the fingerprints were made by the same person. How many similarities do they need to find? That varies by jurisdiction, from as few as 8 to as many as 16. Ultimately, the fi 本文来自：英语论文网 【http://www.51lunwen.org】