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DEVELOPMENT REVIEW

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DEVELOPMENT REVIEW The type of surface on which a fingerprint is deposited has a lot to do with the type of print that will be deposited on the physical evidence – PowerPoint PPT presentation

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Title: DEVELOPMENT REVIEW


1
DEVELOPMENT REVIEW
  • The type of surface on which a fingerprint is
    deposited has a lot to do with the type of print
    that will be deposited on the physical evidence
  • The use of sequential processing techniques can
    increase the number of prints found and improve
    the quality of the prints already developed

2
Fingerprint Reagents and Targetsfrom
http//www.ridgesandfurrows.homestead.com/latent_p
rint_development.html
3
Fingerprint Development techniques
  • Amido Black Proteins Blue-black Also Commassie
    blue
  • DFO (1,8-diazafluoren-9-one) Proteins
    Fluorescent Red- A more sensitive Ninhydrin
    analogue
  • Fluorescence examination naturally occurring
    chemicals and contaminants Fluoresce without
    treatment with laser sensitive dyes.
  • Gentian violet or crystal violet fatty acid
    purple color- good on sticky side of adhesive
    tape-Toxic- Yellow-orange laser light source
    (578nm) Alternate- Fuchsin- Green excitation
    (500nm)
  • Iodinegood on both porous and non porous- fuming
  • Ninhydrin porous surfaces like cardboard,
    wallboard, paper, wood amino acids purple
    colorRuhemanns purple. Treatment with Zn
    chloride and lasers improve sensitivity
  • Physical Developer PD, SPD Sliver based
    solution porous surfaces that are wet or have
    been wet sweat gray to black
  • Powders smooth non porous color depends on
    choice
  • Silver nitrate chlorides in prints
  • Small particle reagent SPR wet surfaces
    molybdenum disulfide in detergent lipids gray
    deposit. Non porous surfaces.
  • Sudan Black non porous oily or greasy surface
    lipids blue black color
  • Superglue or cyanoacrylate fuming non porous
    surfaces white. May be dusted with powder or
    washed with laser sensitive dyes such as
    Rhodamine G-6
  • Vacuum metal deposition VMD smooth non porous
    surfaces gold or zinc thin film on latent
  • See www.fbi.gov/hq/lab/fsc/backissu/jan2001/index.
    htm.

4
AUTOMATED FINGERPRINT INDENTIFICATION SYSTEM
  • AFIS The ability to compare a fingerprint found
    at the crime scent with a criminal fingerprint
    computer data base
  • Cold Searches searching a data base of several
    million prints against a single latent print in
    about 10 minutes

5
LATENT PRINTS
  • CHANCE IMPRESSIONS
  • REQUIRE TRANSFER MEDIUM
  • ENVIRONMENT DEPENDENT

6
Fingerprint Visualization
  • At the Crime Scene
  • Dust and Lift (powders various colors)
  • Magnabrush (iron filings and powder)
  • In the Laboratory
  • Ninhydrin for paper
  • Superglue in tank (sometimes at scene)
  • Other (physical developer, etc.)

7
NINHYDRIN EXAMPLE
8
(No Transcript)
9
(No Transcript)
10
AFIS HIT EXAMPLE
11
FINGERPRINT LAB
  • PART TWO
  • C. Your Inked or pencil Prints
  • What fingerprint patterns ?
  • Enlarged print (at least one characteristic)
  • D. Super Glue
  • 1 item- glass slide
  • PART ONE TODAY
  • A. Black Powder
  • 2 different surfaces
  • Smooth glass slide and tile
  • B. Magnetic Powder
  • 2 different surfaces
  • Smooth glass slide and tile

12
E. Evidence Sample
  • Everyone will get an item to process for
    fingerprints using techniques you have learned/
    MUST LIFT A PRINT
  • HOWEVER!!! MUST SWAB BOTTLE FOR SALIVA FIRST
    (lightly moistened swab)
  • Allow swab to dry while you work on item
  • When dry package in envelope
  • Once swabbed, dry the swab and then place into
    envelope and fill out the chain of custody
  • Be sure to take notes on the evidence and sketch
    on the card.

13
REMINDERS
  • MAKING A LATENT PRINT VISIBLE
  • Place some powder in lid, not too much, circular
    sweeping motion, just grazing surface

14
REMINDERS
  • LIFTING A LATENT PRINT ONTO A FINGERPRINT CARD

Fingerprint card glossy side Dont forget info on
other side!
15
SOURCES
  • Criminalistics/ Chapter 14 / Saferstein
  • http//www.fbi.gov/hq/lab/org/lpu.htm
  • http//www.onin.com/fp/
  • Kendall FG, Rehn BW. 1983. Rapid Method of Super
    Glue Fuming Application for the Development of
    Latent Fingerprints. Journal of Forensic Science.
    28(3) 777-780.
  • Lewis, LA. et al. 2001. Processes involved in the
    development of latent fingerprints using the
    cyanoacrylate fuming method. Journal of Forensic
    Science. 46(2) 241-246
  • California Dept. Justice/ Physical Evidence
    bulletin-PEB 16-17
  • International Association of Identification
  • (IAI)-gt http//www.theiai.org
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