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Specific Heat Capacity Thermal Function of the Cyanoacrylate Fingerprint Development Process, 2012

NCJ Number
Date Published
March 2012
32 pages
There are many existing methods for evolving and visualizing fingermarks with cyanoacrylate (CA); the current research aimed to produce methods for enhancing fingermark recovery.
The research involved five undertakings, each designed to either increase the ease of fingermark development or increase the sensitivity of the fingermark development process. The first method explored the development of sublimation-based co-polymerized coloring. Colored CA fingermarks detectable with a 530 nm laser were successfully produced. The second method explored was the modification of evidence temperature. This method improved fingermark visibility due to an increase in opacity and color uptake of CA fingermarks when the evidence is cooled 6 degrees F - 20 degrees F. The third method explored was the use of infrared detection. After being aged for 2 weeks to allow them to fade, fingermark samples were then examined with infrared cameras at ambient temperature and cooled to force condensation and improve infrared visibility. Although fingermarks were produced, no prints were resolved that would not have been detectable with more economical visible-light means. The fourth undertaking of the research was to find a way to disperse nano-particles onto CA prints. Nano-particles can be applied in a variety of ways, ranging from spraying liquid dispersions to creating dust clouds; however, when the particles are produced on the fingermark itself, it is possible to lock the color into the CA matrix with subsequent fuming. Carbon black non-particles were therefore produced by burning oil and directing the vapor stream onto the print. The fifth aspect of the research involved developing a commercially viable temperature and humidity-controlled chamber to chill the evidence and allow for standard fuming. A unit was developed and can be purchased through Sirchie Corporation. 32 exhibits and 2 references

Date Published: March 1, 2012