VISUAL EXAMINATION

Return to: Main Page   ||  Porous Surfaces  ||  Non-Porous Surfaces  ||  Non-Destructive  ||  Post-Cyanoacrylate  ||  Post-Ninhydrin  ]

Technique Name:
Visual Examination
Surface Used On:
Non-Destructive for all surfaces.
Sensitive To:
Reflected & Absorbed lighting.
Development Color: Method to Record: Hazard: Protective Clothing: Fume Hood Use:

N/A

Not

Not
Reagent Characteristics

Development Complete When:

Source of Error:

Incompatibilities:

Precautions:

Storage Container:

Safety:

Recommendations:


Similar Reagents



Sequential Reagents
(Not necessarily in this order.)



VISUAL EXAMINATION FORMULA:
Not Applicable.
PROCEDURE OF APPLICATION
A. Simple ambient light.

B. Absorbed light
(filter out background color).

C. Reflected light.
(for greasy impressions).

E. Directed light
(to subdue surface texture).

D. Oblique light
(for dust impressions).

E. Transmitted light
(on transparent surfaces).	



Ridge Detail Visualized by:

Visible stain.


Reagent Applicabilities:

Porous sufaces
Non-Porous surfaces


Other Chemical Name(s):

Ambient light
Natural light
Absorbed light
Reflected light
Directed light
Oblique light
Transmitted light


Process Summary:
A non-destructive technique to detect the presence of visible friction ridge detail. Several natural light sources and artificial sources of light may be utilized in order to best visualize any friction ridge detail that is present. The angle of the light source is often varied in an attempt to best visualize the subject.
Accepted Deviations:
Adjusting the source, angle, and illumination intensity may produce better visualization results. Numerous lamps, colored filters, fiber optic guides, liquid light guides and forensic light sources can be utilized.
Supporting Reference Materials:
1. Advances in Fingeprint Technology 2nd. Ed., Lee, H.C. & Gaensslen, R.E., CRC Press, Boca Raton, FL., 2001.
2. Manual of Fingerprint Development Techniques 2nd. Ed., Home Office - Police Scientific Development Branch, White Crescent Press, Ltd., Luton, England, 2001.

Return to: Main Page   ||  Porous Surfaces  ||  Non-Porous Surfaces  ||  Non-Destructive  ||  Post-Cyanoacrylate  ||  Post-Ninhydrin  ]