1. A method of obtaining and analyzing a sample from a subject through interaction with an interactive security screening system comprising: pressing an object associated with the subject upon a sample collection sheet positioned over a contact pad, said object exerting an amount of pressure upon the contact pad; sensing the amount of pressure applied to the contact pad through portions of the sample collection sheet; analyzing whether the amount of pressure sensed is sufficient to indicate that a proper sample has been obtained on the portions of the sample collection sheet; and analyzing the portions of the sample collection sheet with a sample processing system that scans the proper sample for threat residue.