When a person flexes the hand to make a fist, the dorsalside skin near the knuckles tightens. When the fist is relaxed, the skin may fold, creating lines variously called wrinkles and creases.1 In a recent case, these lines were the evidence that was used to try to identify a defendant. The charges against the defendant, Devin Whitfield [1], included child pornography. Part of the evidence consisted of an image taken on a cell phone that included the dorsal side of knuckles. The prosecution called a qualified fingerprint analyst. In light of her expertise in fingerprint analysis, it is useful to review the similarities and differences between knuckle creases and fingerprints.