Let's try this again...
When you touch a glass or a doorknob or whatever, you leave behind an IMAGE of your fingerprint. That image can then be compared to other IMAGES to see if they match.
Biometric finger scanning technology DOES NOT incorporate images as part of the scanning process. When you touch the sensor, it looks at the ridges, curvature, etc on your finger, utilizes a mathmatical algorythm and produces a number for your finger. Next time you enter, it looks at your finger, does the calculation and then goes out to the database to compare that number to the original.
Now... if somebody stole something in the park and left a fingerprint on the door going out of the store, they CAN NOT compare that fingerprint image to the scans taken at entry to identify the thief. The number generated by the scan has zero backwards ability to create a fingerprint image.
Hopefully, that makes it a little clearer for everyone. :wave: