NCJ Number
141743
Journal
Journal of Forensic Sciences Volume: 38 Issue: 2 Dated: (March 1993) Pages: 391-401
Date Published
1993
Length
11 pages
Annotation
A major research program was undertaken to identify magnetic flake product ranges suitable for bright fingerprint development on dark surfaces.
Abstract
Materials included in the study were all available in powder form, sufficiently ductile for the powders to be mechanically deformed to flake morphology, magnetic, magnetically soft, and highly reflective in flake form. The powders selected for testing included cobalt, nickel, austenitic stainless steel, ferritic stainless steel, carbonyl iron, and pure iron. In this study, the milling conditions were selected to ensure that all the flake powders had comparable dimensions. Print brightness seemed to be influenced by chemical composition, flake size, flake surface characteristics, and general shape. Impressive results were obtained with spherical carbonyl iron and austenitic stainless steel powders. Magnetic flake produced from irregularly shaped iron powder was an excellent medium for dark print development. The qualities of the prints revealed on smooth surfaces using these powders were comparable to those developed with commercial aluminum flake powders and, for development of prints on rough surfaces, surpassed even the commercial products. 1 table, 4 figures, and 7 references