Actually they do keep them on file, but not in their criminal database, they only keep them for one year. If for example you are a teacher, you must do them again yearly to keep up with your certification. However this is not a utilized database in searching for prints left at a crime scene, they can only utilize prints that were taken during an arrest. That is a shame, it would really help them if they changed this policy. I know people have the right to privacy, but I would not have a problem with them look at my prints, no innocent person would. IMHO