FIS 201 – Exam 3 Study Guide (WVU)
sweat and sebum are secreted by pores and spreads along skin ridges that are deposited upon
contact - ANS✔✔ how are fingerprints made?
-on hands and soles of feet
-consistent throughout life - ANS✔✔ friction ridges
-they don't change on their own
-damage must be done to the dermal layer of skin (burns, scars) - ANS✔✔ can fingerprints
change over a lifetime?
-prints unable to be seen
-require enhancement (powders, chemicals, light) - ANS✔✔ latent fingerprints
-prints able to be seen
-don't require enhancement
-created by sticky low-flow materials (blood, ink, grease) - ANS✔✔ patent fingerprints
3D capture of a print in soft, fine-grained materials - ANS✔✔ plastic impression
paper, cardboard - ANS✔✔ porous substrates
metal, plastic, glass - ANS✔✔ nonporous substrates
-targets nonporous substrates
,-dust sticks to sebum on fingerprints - ANS✔✔ fingerprint dusting
areas most likely to have been touched by the suspect
-door handles/frames
-windows
-furniture/appliances
-vehicles - ANS✔✔ fingerprint target locations
1. photograph the dusted print
2. press fingerprint lifting tape across the print
3. gently smooth tape flat
4. lift off the print
5. press it over a lift card - ANS✔✔ steps to lift a print
-smaller, high touch objects
-smooth, dry shapes
-all porous materials - ANS✔✔ evidence collected at crime scenes
10 print card of rolled fingerprints from a known human - ANS✔✔ fingerprint exemplar
chemical name for superglue - ANS✔✔ cyanoacrylate
-enhancement and protection of latent fingerprints on nonporous substrates
-forms a plastic polymer built up from the print - ANS✔✔ cyanoacrylate fuming
, fumes bind to fats in the presence of water - ANS✔✔ what do cyanoacrylate esters stick to on a
fingerprint?
-detection on porous substrates only
-forms "Ruhemann's purple" - ANS✔✔ ninhydrin
reacts with amino acids in sweat - ANS✔✔ what does ninhydrin react with on a fingerprint?
purple dye that works well to enhance fingerprints on clear tape - ANS✔✔ gentian violet
works on formerly wet substrates - ANS✔✔ small particle reagent (SPR)
molybdenum disulfide particles react with lipid components - ANS✔✔ what does SPR react with
on fingerprints?
-temporarily turns latent fingerprints brown
-requires photograph - ANS✔✔ iodine fuming
evaporated vapors react with sebum (oils/lipids) - ANS✔✔ what do iodine fumes react with on
a fingerprint?
oils, moisture, sebum - ANS✔✔ what do fingerprint powders stick to on a fingerprint?
-powder suspended in detergent
-colors allow max contrast - ANS✔✔ sticky side/wet wop
frequently touched surfaces are textured for grip - ANS✔✔ textured surfaces
sweat and sebum are secreted by pores and spreads along skin ridges that are deposited upon
contact - ANS✔✔ how are fingerprints made?
-on hands and soles of feet
-consistent throughout life - ANS✔✔ friction ridges
-they don't change on their own
-damage must be done to the dermal layer of skin (burns, scars) - ANS✔✔ can fingerprints
change over a lifetime?
-prints unable to be seen
-require enhancement (powders, chemicals, light) - ANS✔✔ latent fingerprints
-prints able to be seen
-don't require enhancement
-created by sticky low-flow materials (blood, ink, grease) - ANS✔✔ patent fingerprints
3D capture of a print in soft, fine-grained materials - ANS✔✔ plastic impression
paper, cardboard - ANS✔✔ porous substrates
metal, plastic, glass - ANS✔✔ nonporous substrates
-targets nonporous substrates
,-dust sticks to sebum on fingerprints - ANS✔✔ fingerprint dusting
areas most likely to have been touched by the suspect
-door handles/frames
-windows
-furniture/appliances
-vehicles - ANS✔✔ fingerprint target locations
1. photograph the dusted print
2. press fingerprint lifting tape across the print
3. gently smooth tape flat
4. lift off the print
5. press it over a lift card - ANS✔✔ steps to lift a print
-smaller, high touch objects
-smooth, dry shapes
-all porous materials - ANS✔✔ evidence collected at crime scenes
10 print card of rolled fingerprints from a known human - ANS✔✔ fingerprint exemplar
chemical name for superglue - ANS✔✔ cyanoacrylate
-enhancement and protection of latent fingerprints on nonporous substrates
-forms a plastic polymer built up from the print - ANS✔✔ cyanoacrylate fuming
, fumes bind to fats in the presence of water - ANS✔✔ what do cyanoacrylate esters stick to on a
fingerprint?
-detection on porous substrates only
-forms "Ruhemann's purple" - ANS✔✔ ninhydrin
reacts with amino acids in sweat - ANS✔✔ what does ninhydrin react with on a fingerprint?
purple dye that works well to enhance fingerprints on clear tape - ANS✔✔ gentian violet
works on formerly wet substrates - ANS✔✔ small particle reagent (SPR)
molybdenum disulfide particles react with lipid components - ANS✔✔ what does SPR react with
on fingerprints?
-temporarily turns latent fingerprints brown
-requires photograph - ANS✔✔ iodine fuming
evaporated vapors react with sebum (oils/lipids) - ANS✔✔ what do iodine fumes react with on
a fingerprint?
oils, moisture, sebum - ANS✔✔ what do fingerprint powders stick to on a fingerprint?
-powder suspended in detergent
-colors allow max contrast - ANS✔✔ sticky side/wet wop
frequently touched surfaces are textured for grip - ANS✔✔ textured surfaces
