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Tour of Forensic Laboratory

Published on Mar 07, 2016

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PRESENTATION OUTLINE

Tour of Forensic Laboratory

Logan Allio

Alternate Light Source

  • uses lasers and UV light to reveal "hidden" evidence from a crime scene such as latent fingerprints and body fluid
  • bone, teeth, and narcotics also will fluoresce
  • CSI labs spray an area with a chemical such as luminol to help detect evidence

Ballistic Photograph

  • Bullets leave residues that may be photographed or analyzed in the lab
  • each gun leaves characteristic marks on each bullet (like a fingerprint)
  • determines distance, velocity, and angle bullet was fired

Compound Stereo Microscope

  • Can characterize - soil samples, plant parts, glass chards, and clothing fibers.
  • Uses polarized light to determine object density.
  • Can magnify objects as small as 10 microns up to 1000 times.

SEM

  • Scanning Electron Microscopes can magnify the surface of solid objects up to 200,000
  • Evaluates - gunshot residue, firearms identification, investigation of gemstones, paint particles, filament bulbs, handwriting, counterfeit money, and fibers.

TEM

  • Transmission Electron Microscope
  • Sends a beam of electrons through a very thin section
  • can magnify up to 500,000 times
  • TEMS can identify trace evidence and determine time of death

Fume Hood

  • For working with gases, acid fumes, and chemical vapors.
  • Chemicals are typically liquids
  • Designed to capture and exhaust contaminates resulting from working with chemicals.

Centrifuge

  • Use for physical separation, based on density.
  • Centrifugal force created by spinning separates mixtures based on particle size and the difference in density between liquid and solid phases in the tube.
  • Uses - DNA concentrations, spearating componenets of blood and urine prior to drug testing

Chromatograph

  • Chromatographs contain two phases - stationary and mobile
  • Stationary is placed in the column and stays still
  • Mpobile phase is pumped in and carries the analyte throuhg the stationary phase

Spectrometer

  • A mass spectrometer can identify each component as it emerges from a column.
  • The atoms of a chemical are evaluated based on teh atomic mass
  • Only a small sample is needed
  • Scientists use the unique mass spec tdiagram to compare the two samples and see if they match.

Solid-Phase Extraction

  • Used to concentrate and purify samples for analysis
  • can be used to isolate analytes of interest from a variety - urine, blood, water, beverages, soil, and animal tissue
  • can be used to identify organiz explosives on plastic surfaces

Computer

  • Computers can be used to extract digital evidence
  • databases are another way computers are helpful
  • types of crime investigated through digital evidence - murder, theft, fraud, extortion, espionage, pornography, SPAM, viruses, property breaches, forgery, perjury

Imaging

  • Imaging is a complete copy of a hard drive or other digital media, generaly intended for use as evidence

Databases

  • Examples of Databases - fingerprints, handwriting, firearms, DNA, paint, shoes, drugs, biometric databses
  • The fingerprint databases are the oldest - matches algorithms to compare handwriting samples

Databases (cont)

  • Fish system - analyzes upper and lower loops , Script system analyzes interline and inter-word distances and slants
  • CODIS - Combined DNA Index System 0 FBI's program of support for criminal justice DNA
  • NDIS - National DNA Index System - contains DNA profiles of participating forensic labs

NCIC

  • The National Crime Information Center is a computerized database of documented criminal justice information availiable to virtually every law enforecement agency nationwide.

Real World Use

  • In order to trace a piece of paint back to a specific item, a SEM can be used to magnify the paint chip by 200,000 times to be more closely identified.

Citations

  • "Fingerprint Analysis." : How It’s Done. N.p., n.d. Web. 07 Mar. 2016.
  • "Stereo Microscope Basics." Stereo Microscope Basics. N.p., n.d. Web. 07 Mar. 2016.
  • "MyScopetraining for Advanced Research." Layout. N.p., n.d. Web. 07 Mar. 2016.
  • "Transmission Electron Microscope (TEM)." Transmission Electron Microscope (TEM). N.p., n.d. Web. 08 Mar. 2016.

Citations

  • "Ballistic+photograph - Google Search." Ballistic+photograph - Google Search. N.p., n.d. Web. 08 Mar. 2016.
  • Wikipedia. Wikimedia Foundation, n.d. Web. 08 Mar. 2016.
  • "Hettich EBA20 Portable Centrifuge - Small Bench Centrifuges - Centrifuges (UK Centrifuge Sales, Service for Centrifuges)." Hettich EBA20 Portable Centrifuge - Small Bench Centrifuges - Centrifuges (UK Centrifuge Sales, Service for Centrifuges). N.p., n.d. Web. 08 Mar. 2016.

Citations

  • "Chromatograph - Google Search." Chromatograph - Google Search. Carlton.edu, n.d. Web. 08 Mar. 2016.
  • "Educational Spectrometer." - Exporter, Manufacturer & Supplier, New Delhi, India. N.p., n.d. Web. 08 Mar. 2016.
  • "Laboratory Supplies & Lab Equipment - Centrifuges, Lab Apparatus, Lab Glass, Ph Meters, Labware, Medical Supplies & More." Labplanet Blog. N.p., n.d. Web. 08 Mar. 2016.

Citations

  • "Computer." Essay And Paragraph. N.p., n.d. Web. 08 Mar. 2016.
  • "Advanced Methods Assist in Scene-of-crime Investigations and Post-mortems." Advanced Methods Assist in Scene-of-crime Investigations and Post-mortems. N.p., n.d. Web. 08 Mar. 2016.

Citations

  • "Part 1: A Look at the Nationwide System That Helps Solve Crimes." FBI. FBI, 23 Nov. 2011. Web. 08 Mar. 2016.
  • "Ndis+forensics - Google Search." Ndis+forensics - Google Search. N.p., n.d. Web. 08 Mar. 2016.