Formula
Procedure of Application
Development Complete When
Source of Error
Incompatibilities
Precautions
Storage Container
Safety
Recommendations
Sequential Reagent
Formula
Two Options: A. Liquid glue: Deposit an amount of glue about 20 mm in diameter in a small porcelain plate. -- or -- B. Commercial "Gel-pac": Open pack to release fumes. Procedure of Application
Development Complete When
The white crust is polymerized on the impression. Check the progress of polymerization after 5 to 10 minutes. Source of Error
Humidity around 80% relative humidity must be introduced in order to catalyze the non-specific polymerization reaction. Gel-Pac may be exhausted of the active ingredients. Incompatibilities
Moisture-laden surfaces. Items to be submitted for Firearms and Biology examination. Light-colored surfaces which present little contrast for the developed detail. Precautions
Don't breathe the fumes after opening the processing tank. Let the fumes escape from the tank before removing the items. Store & examine the treated item in a well-ventilated area. Storage Container
Gel-pacs can be stored in zippered plastic bags. Safety
Ventillation in the area of fuming tanks is required. Cyanoacrylate is an irritant if inhaled. Recommendations
View using oblique white light to visualize any faintly developed prints. Use a post-cyanoacrylate dye stain to improve the visualization of any developed detail. Researchers recommend to let the developed detail 'sit' overnight before treating with dye stains. Sequential Reagent
Not Necessarily in this Order: Vertical Divider
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Chemical Name
Cyanoacrylate Ester Surface Used On Non-Porous Surfaces Sensitive To Eccrine Components Abridged Reagent Sequence
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Ridge Detail Visualized by:
Visible chemical/stain reaction Reagent Applicabilities: Non-Porous surfaces Other Chemical Name(s): Superglue Ethyl-2-Cyanoacrylate Methyl-2-Cyanoacrylate Working Solution Shelf-life: Indefinite |
Process Summary:
An item for processing is placed within an enclosed chamber. Fumes from the active ingredient of Cyanoacrylate ester polymerizes on the components of the impression's residue creating a white impression. Several post-cyanoacrylate dye stains or powders may be applied to improve the visualization of the developed detail.
An item for processing is placed within an enclosed chamber. Fumes from the active ingredient of Cyanoacrylate ester polymerizes on the components of the impression's residue creating a white impression. Several post-cyanoacrylate dye stains or powders may be applied to improve the visualization of the developed detail.
Accepted Deviations:
Many forms of superglue fuming, fuming acceleration and chamber construction may be used for evidence processing. Items may also be processed with Cyanoacrylate ester using vacuum chambers.
Many forms of superglue fuming, fuming acceleration and chamber construction may be used for evidence processing. Items may also be processed with Cyanoacrylate ester using vacuum chambers.
Supporting Reference Materials:
- Lee, H.C. and Gaensslen, R.E. (1984), "Cyanoacrylate Fuming: Theory and Procedures".
- "Chemical Formulas and Processing Guide for Developing Latent Prints", U.S. Dept. of Justice, pg. 47-48, 1994.
- Advances in Fingeprint Technology 2nd. Ed., Lee, H.C. & Gaensslen, R.E., CRC Press, Boca Raton, FL., 2001.
- Manual of Fingerprint Development Techniques 2nd. Ed., Home Office - Police Scientific Development Branch, White Crescent Press, Ltd., Luton, England, 2001.
- Technical Notes, Lightning Powder Co. Inc., Salem, OR., 2001.