Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
36 Cards in this Set
- Front
- Back
|
What must you do before processing documents? |
Photograph/photocopy |
|
|
SU porous processing sequence |
Visual Inherent luminescence (ALS) Iodine fuming DFO Laser/ALS Ninhydrin PD |
|
|
Iodine fuming |
Crystals sublime with heat application PHYSICAL INTERACTION Reacts with Lipids & Sebaceous Temporary, but can be fixed with 1% starch solution Non-destructive Can make multiple lifts. |
|
|
DFO (1,8-diazafluoren-9-one) |
USE BEFORE NINHYDRIN IN SEQUENCE Chemical Reaction Reacts with Amino Acids Application: Dip item, air dry Paint item, air dry Spray item, air dry Development: Heat item with DRY iron or in DRY oven DRY HEAT Visualization: Color mode (usually weak) Fluorescence mode Blue/cyan (450-530 nm) with orange filter |
|
|
Ninhydrin |
USED BEFORE PD IN SEQUENCE
Chemical reaction Reacts with Amino Acids Reaction produces RUHEMANN'S PURPLE
Application: Dip item, air dry Paint item, air dry Spray item, air dry
Development: Allow gradual development overnight Or Heat item with steam iron or in humidified oven
WET/HUMID HEAT
sidenote: ninhydrin has quenching effect on DFO fluorescence. Visualization: Color mode (purple) NO FLUORESCENCE MODE Absorbs at 407 nm (Violet) and 582 nm (green-yellow) |
|
|
Physical Developer (PD) |
USE LAST IN SEQUENCE Silver-based aqueous reagent Develops old prints (30-40 years) Chemical reaction Reacts with Sebaceous sweat (sebum, lipids) Dark gray/silver Application: Acid pre-wash Soak item in working solution Several rinses/air dry/photo |
|
|
1,2-indanedione |
Replacing DFO/NINHYDRIN
Chemical reaction Reacts with Amino Acids
Application: Dip item, air dry Paint item, air dry
Development: Heat item with DRY iron or in DRY oven
Visualization Color mode--yellow FLUORESCENCE mode 515-570nm orange/red filter |
|
|
Oil Red O |
Alternative to PD USED LAST IN SEQUENCE Lipid stain Dyes red Application: Immersion in staining solution Immersion in buffer solution Rinse in distilled water |
|
|
Thermal paper processing techniques |
Option 1: Removal of thermal coat using acetone Then process using SU sequence
Option 2: Ground NINHYDRIN crystals applied with brush
Option 3: Sublimated NINHYDRIN crystals used to fume
Option 4: Filter paper impregnated with DFO or NINHYDRIN, dried, then applied.
Option 5: Muriatic acid fuming Fumes will develop blue-black print Impermanent 35 days Sebaceous and Amino acids targeted
Option 6: Ethanol/HFE wash Process thermal paper with regular solvent(s) Dip blackened paper in 15:85 ethanol:HFE 7100 solution to remove the black discolorationCA and Mag powder 7100 solution to remove the black discoloration CA and Mag powder
Option 7: Low heat application utilizing a hairdryer Destructive if over heated |
|
|
ThermaNin |
2 g ThermaNin crystals 2.5 ml isopropanol 7.5 ml ethyl acetate 490 ml petroleum ether |
|
|
Thermal Paper Sequence SU sequence |
Visual Inherent luminescence CA fuming Iodine--dissipates, but destroys ThermaNin--targets Amino acids Low heat application--most destructive Magnetic powder |
|
|
Bloody Prints |
Fixation of blood on surface prior to chemical treatment 5-sulfosalicylic acid Precipitates proteins--not soluble Does not prevent DNA swab. |
|
|
Amido Black |
Protein stain Requires rinse Permanent Can be used on porous or non-porous |
|
|
Leucocrystal Violet |
Enhances blood--catalytic oxidation of the dye Chemical reaction Reacts with heme group No rinsing required Fixes the blood impression Colorless-->purple
Can be used for porous and nonporous Other blood enhancement techniques such as Amido Black may be applied after. |
|
|
Hungarian Red |
Protein stain for impressions in blood Colors print red Fluorescent using 510 to 560 nm (green) and a red barrier filter |
|
|
Bloody Prints for non-porous surfaces |
Hungarian Red Amido Black LCV Non-porous surfaces |
|
|
Bloody prints on porous surfaces |
Reacts with Amino acids DFO NINHYDRIN 1,2-Indanedione |
|
|
Processing Sequence for Porous Blood Stained Items |
Visual Laser/ALS DFO Laser/ALS NINHYDRIN Amido Black--larger Amino acids PD--reacts to lipids |
|
|
Processing Sequence for non-porous blood stained items 1 |
Visual Inherent luminescence Laser/ALS Fixative before blood reagent is applied Hungarian Red OR Gelatin lifter Laser/ALS |
|
|
What is a latent print? |
A transferred impression of the friction ridges of all or any part of the finger not readily visible. |
|
|
SU crime scene latent print examination sequence |
Visual Photo Flashlight Photo Als Photo Powder Photo Lift Photo |
|
|
SU laboratory latent print examination sequence |
Visual Photo Inherent luminescence Photo CA Photo Option dye stain Photo Powder Photo Lift |
|
|
Gentian Violet targets what constituents of the latent print? |
Epithelial cells/ skin tissue |
|
|
The most common insensitive dye stain use after CA to enhance visualization on non-porous objects is: |
Rhodamine |
|
|
Deposition factors |
Pre-transfer conditions -condition and health of skin Transfer factors -substrate characteristics -lateral movement Post-transfer factors -weather conditions -alteration by another person |
|
|
Secretion of eccrine gland that is of primary importance to development of latent print ridge detail: |
Amino acids |
|
|
The primary compounds present in Sebaceous secretions: |
Sebum |
|
|
SPR is used on what types of surfaces? |
Nonporous and wet. |
|
|
Rhodamine 6G (a component of RAM) can be used in conjunction with an alternate light source in order to visualize latent prints. What is an appropriate wavelength and what color camera or barrier filter should be used after the impressions have been treated for rhodamine 6G? |
415-530, orange barrier filter |
|
|
The following wavelengths should be used in order to visualize latent prints treated with Ardrox: |
380nm |
|
|
Fluorescence vs. Phosphorescence |
FLUORESCENCE: luminescent only went under source creating higher wavelength. Phosphorescence: luminescent even after the energy source has been removed. |
|
|
Barrier filters and wavelengths |
UV-444 yellow 444-515 orange 515-550 red |
|
|
light energy acts on an object in four basic ways. Fluorescent examinations, employing the use of an alternate like source, are primarily concerned with which of the following? |
Converted light |
|
|
Tuesdays presentation: what methods were best to process prints that had been submerged in water on non-porous and porous surfaces respectively? |
Nonporous: CA Poroys: PD |
|
|
Atlanta twin murder case study |
Bertillon system--measuring body parts Volar pads develop 6-8 weeks gestation Friction ridge skin develops 11 weeks gestation |
|
|
Processing sequence for non-porous blood-stained items 2 |
Visual Inherent luminescence Amido Black CA ALS/laser Chemical dye stains ALS/laser/UV Powders |
