Based in Columbia, South Carolina, attorney Stephen Krzyston practices with Cavanaugh & Thickens, LLC, providing criminal defense representation in diverse court settings. Among Stephen Krzyston’s areas of extensive experience is crime scene reconstruction. He is familiar with collection methods involving latent, plastic, and patent fingerprints.
Patent fingerprints are the type of prints that are clearly visible to the naked eye and occur when the skin on the finger comes into contact with a substance such as ink, grease, blood, or dirt. Plastic fingerprints, meanwhile, are three dimensional and are created by pressing the finger into substances such as wax, soap, fresh paint, or tar. As with patent fingerprints, they are easy to make out with the visible eye. By contrast, latent fingerprints involve an impression left by the oil and sweat on the skin’s surface and require additional processing to be made visible.
A determiner of the type of print collection method used is the characteristic of the surface on which it is found. The three basic surface types are porous, non-porous rough, and non-porous smooth.
Porous surfaces, which absorb liquids, include paper and untreated wood. For these, technicians sprinkle chemicals such as ninhydrin over the prints to develop them. For non-porous smooth surfaces such as plastics and glass, powder and brush techniques are accompanied by lifting tape. When it comes to non-porous rough surfaces, technicians will use the powder and brush in tandem with a gel-lifter or silicone casting material that can get into the surface’s grooves.
