PHYSICAL DEVEOPER

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Chemical Name:
PHYSICAL DEVEOPER		 Surface Used On:
Porous surfaces, especially currency & paper. Effective on wet items.		 Sensitive To:
Sebaceous components.
Development Color: Method to Record: Hazard: Protective Clothing: Fume Hood Use:

Black
Not
Reagent Characteristics

Development Complete When:

Source of Error:

Incompatibilities:

Precautions:

Storage Container:

Safety:

Recommendations:

Similar Reagents


Sequential Reagents



Abridged Reagent Sequence

Visual Examination
|
Forensic Light
|
D.F.O.
|
Ninhydrin
|
*** Physical Developer ***
|
Sodium Hypochlorite

 PHYSICAL DEVEOPER FORMULA:
1.
Maleic acid pre-wash:

50 grams Maleic acid powder
dissolved in 2 liters 
of distilled water.

2.
Commercial Working Solution:

1 part solution A 
   (5ml. /10ml. /15ml.)

To 18 parts solution B 
   (90ml./180ml./270ml.)
PROCEDURE OF APPLICATION 
A.
 Pre-wash (10 minutes)
B.
 Working solution
	(20 minutes)
C.
 Rinse (5 minutes)
D.
 Rinse (5 minutes)


Ridge Detail Visualized by:

Visible chemical/stain reaction.


Reagent Applicabilities:

Porous sufaces
Post-Ninhydrin
Raw Wood surface
Wet surface


Other Chemical Name(s):

P.D.


Working Solution Shelf-life:

Prepared as needed.
Process Summary:
This is a multi-solution, multi-step process that can be used as a follow-up to ninhydrin cases. This is the technique of choice for paper currency items, and porous items that may have been wet.
Accepted Deviations:
Commercial or Laboratory-prepared mixtures are used. Physical Developer also develops indentations in paper surfaces, therefore FW/TT impressions may be enhanced.
Supporting Reference Materials:
1. Technical Note No. 1-2730 "Physical Developer Kit", Lightning Powder Co., Inc. (1990)
2. "Manual of Fingerprint Development Techniques 2nd. Ed., Home Office - Police Scientific Development Branch, White Crescent Press, Ltd., Luton, England, 2001.
3. Navarro, R.L., "Chemical Enhancement of Questioned Footwear Impressions", North Carolina State Bureau of Inv., 1992.
4. "Chemical Formulas and Processing Guide for Developing Latent Prints", U.S. Dept. of Justice, pg. 47-48, 1994.
5. Advances in Fingeprint Technology 2nd. Ed., Lee, H.C. & Gaensslen, R.E., CRC Press, Boca Raton, FL., 2001.
6. Technical Notes, Lightning Powder Co. Inc., Salem, OR., 2001.

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