Could someone use a picture of a registered users fingerprint to gain access into a biometrics system?
No. The fingerprint verification module looks for a live three-dimensional scan of the fingerprint. In addition to the length and width of unique characteristics of the fingerprint, the verification module looks for the third dimension of depth which is determined by the shadow cast by these unique characteristics; i.e., ridges, whorls, loops, bifurcations, etc. There are still other devices that actually look for an electrical charge from a live fingerprint during the scanning process. The user must make contact with their scanning finger with the metal as well as the sensor platen of the scanner for a proper fingerprint scan.