Fifty-four fingerprints were collected with the ESDA collection
technique, which was performed utilizing the ESDA-Lite (Foster
and Freeman, United Kingdom), followed by wet/dry swabbing of
the portion of the Mylar film that came into contact with the
fingerprint. To prevent sample cross-contamination, samples were
not permitted to make direct contact with the vacuum bed of the
instrument. Before each sample was placed on the ESDA-Lite, a
clean sheet of copy paper was placed directly on the vacuum bed
(Fig. 1a), and the sample was placed on the paper. After this, the
vacuum was started, and Mylar film was carefully placed over the
sample (Fig. 1b). To initiate an electrostatic charge, the corona
wand was turned on and slowly waved horizontally and vertically
over the plate at a height of approximately three to five
centimeters (Fig. 1c).