Search for fibers
Prepare microscope slide
Cargille high dispersion
refractive index = 1.525
forceps wetted with liquid
sort by type

ANIMAL FIBERS
sheep - wool goats - mohair, cashmere camels, llamas, alpacas, vicunas mink, rabbit, beaver, muskrat.

CASE -
RABBIT HAIRS ON FLOWER BOX, BOX LINING, AND VICTIM'S COAT ASSOCIATING VICTIM AND
BOX AND LINING.

NATURAL FIBERS
Cotton
ribbon like shape with twists at irregular intervals
medulla size and shape
hair size and shape

MANUFACTURED FIBERS
Rayon first made in 1911
First fibers were regenerated fibers - cotton or wood pulp
most fiber totally manufactured
synthetic, long chained molecules - polymers
Nylon in 1939

Monomers complex organic molecule
Polymer - long repeating strings

U.S. Federal Trade Commission study found that In 1983 75% of the fibers examined by forensic scientists
    were Nylon or acrylic
Nylon trilobal cross section.
Polyesters such as Dacron---smooth and tightly woven
                                            do not shed particles.
delustering fibers -

titanium dioxide -
reduce the shine

Manufactured fibers linear arrangements of molecules behave like crystals
Light polarized perpendicular and parallel to fiber length

ATOMIC ABSORPTION SPECTROPHOTOMETRY
Periodic Table
electrons protons neutorns
specific energy level
absorb the energy -
particular wavelength (color)
jump to higher orbit
energy released spectra to identify materials.
Infrared atomic absorption
spectrophotometer
    Infrared light under a microscope analyze a single fiber
    nondestructive
    Pattern compared to library of spectra of known fibers
   Colors produced by dyes to fiber

CASE
    Box and liner tan wool fibers, red acrylic fibers, navy blue wool fibers consistent with decedents clothing - tan wool    overcoat, navy blue wool/polyester slacks and red acrylic sweater
   On liner and box were found light blue nylon rug fibers, and rabbit hairs
    On coat were found red nylon rug fibers.
    Suspect a light blue and a red carpet in the apartment

The world is full of painted objects - houses, windows, furniture, automobiles etc.
Paint Composition
    Solvent keeps the constituent parts in liquid form
    Binder holds the pigment particles together and onto surface.
    Pigment consists of various organic and inorganic materials which impart color.
Large number of substances used as binders
Same binder type from different chemical combinations.
Same is true of the pigments
The same colored car can be painted with paint that differs in binder and the combination of pigments.

Automobile finishes divided into THREE broad TYPES.
    1.ACRYLIC LACQUERS - used primarily by General Motors.
        Acrylics as the binder composed of long polymer chains
        Few chemical links between chains
        Soluble in acetone.
    2.ACRYLIC ENAMELS - polymers extensively cross linked when the paint is heated
        Very hard and durable
    3.ALKYD ENAMELS - extensively cross linked polymers
        Differ in composition from the Acrylics
        Primarily used by foreign car manufactures

IDENTIFYING OR MATCHING PAINT
******INDIVIDUALIZATION IS KEY*******
    Match the broken edges
    Proceed to characterization of physical and chemical properties
First line of analysis is identifying the color
    layering of paint
    layering sequence of different colors or finish types
Second step is identification of:
    constituent components
    binder and the pigments

GAS CHROMATOGRAPHY
chromatograms or pyrograms
Since 1974 the car manufacturers submitted paint chips to Law Enforcement Standards Laboratory at the National Bureau of Standards. This made it possible to identify make of car, model year, and the manufacturing plant of auto paint.
    Characterize auto paints from 500 wrecked cars can show uniqueness of 16,000 to 1.

Variety of techniques to characterize paints, their binders and pigments
    gas chromatography,
    infrared spectrophotometry,
    emission spectroscopy,
    neutron activation analysis,
    x-ray diffraction,
    x-ray spectroscopy.

CHROMATOGRAPHY -
    Separation of a substance into its constituent molecules
    Concepts of solubility and equilibrium between phases.

GAS CHROMATOGRAPHY
    Use the liquid and gas phases
    Amount of the substance which evaporates depends upon its solubility in the fluid.
    Molecules will evaporate entering the gas phase as dissolve in the fluid and enter its liquid phase
    Equilibrium
    Vary in solubility
    Differing proportions between their liquid and gas phases
    Any substance which has more of its molecules in the gas phase will move faster
    Substances can be separated by their differing speed of movement
GAS CHROMATOGRAPHY
    Gas forced through a tube or collum of glass or stainless steel
CARRIER GAS -
    usually nitrogen or helium.
Capillary Column
    Dissolved in a solvent - (acetone for ACRYLIC LACQUERS)
    injector area and is quickly transported away by the moving carrier gas
    Moves through capillary tube of Gas Chromatograph
    Its component parts are separated as the more soluble substance moves slower
    Chamber is heated
    Gases enter the detector - each in sequence
    Flame is used to ionize the gases
    Detecting device sends a signal which is recorded
    Strip recorder component parts are recognized as peaks which vary in width and separation between components based    on the time delay of their arrivals at the end of the capillary tube
    The pattern of peaks, their widths, and distances between them are unique to each substance which varies by its component parts.
    This technique is not definitive because it does not tell you what the components are
    Library of finger prints can compare the patterns and identify the unknown substances by matching

PYROLYSIS GAS CHROMATOGRAPHY
    For things that are not dissolvable
    heated to high temperatures---500 to 1000 degrees centigrade
    Heated or pyrolyzed

CHROMATOGRAM OR PYROGRAM.

Federal, state and local laws
CONTROLLED SUBSTANCES ACT
There are 5 schedules ranked by the drugs potential for abuse
    Schedule I: high potential for abuse, no medical value, and/or lack accepted safety for use in treatment under medical supervision.  Include: heroin, marijuana, methaqualone, and LSD.
    Schedule II: high potential for abuse, currently accepted medical use with severe restrictions, potential for severe psychological or physiological dependence.  Include: cocaine, methadone, phencyclidine (PCP), amphetamine preparations, and barbiturates.
    Schedule III: less of a potential for abuse, current medical use, have a potential for low or moderate physical dependence or high psychological dependence.  Include: all barbiturates except phenobarbital and certain codeine preparations.
    Schedule IV: low potential for abuse and current medical use, limited dependence.  Include: Darvon, phenobarbital, meprobamate, Valium, and Librium.
    Schedule V: low abuse potential, medical use, less potential for dependence: opiates with nonnarcotic medicinal ingredients.

NARCOTIC DRUGS
opium, heroin, Darvon
HALLUCINOGENS
Marijuana, LSD (lysergic acid diethylamide, STP (dimethoxymethylamphetamine), DMT (dimethyltryptamine), mescaline, PCP (phencyclidine), and psilocybin.
DEPRESSANTS
Alcohol, barbiturates (amobarbital, secobarbital, phenobarbital, pentobarbital, and butabarbital), tranquilizers (Librium, Valium), glue sniffing.
STIMULANTS
Amphetamines, cocaine, crack.

PROBLEM -illegally manufactured drugs can be cut or diluted with any number of additives

Crime Labs- 75% of the evidence processed is drug related.

Challenge comes in selecting analytical procedures that will ensure a specific identification of the substance
    1.  Screening test - simple tests - not definitive - but can reduce the possible identifications to a small and manageable number.
    Color tests
    2.  Tests and analytical procedures selected to provide confirmation of the screening test and drug identity.  Here we bring in the high tech equipment.  Many here will be nonspecific tests.
    3.  Highly specific tests can then be employed that will identify the drug to the exclusion of all other known chemical compounds,
 

SCREENING TESTS
Color Tests
    1. Marquis - heroin, morphine, opium derivatives turn purple with 2% formaldehyde in sulfuric acid.  Amphetamines and methamphetamines turn orange-brown.
    methanol.
    3.  Duquenois-Levine marijuana turns purple in the chloroform layer when treated by solution A - 2% vanillin and 1% acetaldehyde in ethyl alcohol; solution B - concentrated hydrochloric acid; and solution C - chloroform.
    4. Van Urk turns LSD blue-purple when treated with 1% p-dimethylaminobenzaldehyde dissolved in 10% concentrated hydrochloric acid and ethyl alcohol.
    5.  Scott test - cocaine turns blue when mixed with solution A - 2% cobalt thiocyanate in water and glycerine then blue turns clear with addition of solution B - concentrated hydrochloric acid and then blue again with the addition of chloroform.

These tests are not definitive

Microcrystalline tests frequently used screening tests apply a specific chemical to the suspected drug and examine crystal formed against standards great deal of experience they are not empirical

CHROMATOGRAPHY
    Drugs are frequently diluted with anything available. It is the drug that must be identified not the dilutants
    Chromatography is the prime means of separating drug from other substances/chemicals
    Gas chromatography is ideal
    Suspect drug must be analyzed along with a known

THIN LAYER CHROMATOGRAPHY(TLC)
    Moving liquid and stationary solid.
    Glass plate is coated with silica gel or aluminum oxide
    Sample can be placed on plate
    Fluid rises up the granular surface and the sample is carried along with it
    Distance the sample moves dependent upon solubility in the carrier fluid.
    Identified by the Rf value---Distance traveled up the plate divided by the distance traveled by carrier fluid
    A dye or a florescent dye
    Must have reference samples

SPECTROPHOTOMETRY
    Selective absorption of ultraviolet and infrared light producing a finger print pattern, matched to library of known drugs.
    Different materials selectively absorb different colors of light
    Energy of the photon is determined by the wave length of light enters a material
    It differentially absorbs certain colors
    Radiation source light passes through prism or diffraction grating and is split into a continuous spread of wave lengths
    Slit positioned in location of wave length desired
    Passed through the material
    Dissolved in a fluid
    Light passes through the unknown substance is measured by the detector compared to light being transmitted that does not
    pass through the sample
    Specific finger print pattern of absorbed light not definitive
MASS SPECTROGRAPHY
    Introduce a pure substance into a high vacuum chamber
    Bombard with a beam of high energy electrons knock off their electrons
    Molecules are positively charged - ions
    ions are unstable and fragment into smaller pieces
    passed through an electromagnetic field which separates them by the mass
    separated fragments pass through detector which counts each fragment
    Result is a mass spectrum of the fragments--- must be pure
    Use chromatography to divide the sample up into its components
    gas chromatography to do the separations
    workhorse of the drug section of the crime lab.

SPECTROPHOTOMETER
    Light source 420 nanometers
    Potassium dichromate absorbs at this wavelength
    Move the light source away from the test ampule to compensate for more light
    Provides a reading of the blood alcohol level.
Other Devices for measuring BAC --Blood alcohol content
    Infrared breath testing instrument--portable unit with fuel cell converts into electricity
    Verification blood must be collected
    10ml blood
    anticoagulant (EDTA)
    preservative ie. sodium fluoride
    kept refrigerated.
    gas chromatography - automated

TOXICOLOGY
    Toxicologist given organs, tissues or fluids test for drugs or poisons
    Must use information from investigator to narrow what to look for
    distributed through body
    concentrations of nanograms modified by metabolism and degraded after death
    From living obtain two urine voids and 10cc of blood
    Testing blood for alcohol and cocaine content comprises 90% of toxicology laboratory time

First step
divide acidic or basic drugs
SCREENING
1. THIN-LAYER CHROMATOGRAPHY
2. GAS CHROMATOGRAPHY
3. IMMUNOASSAY
CONFIRMATION
GAS CHROMATOGRAPHY - MASS SPECTROMETRY

HEAVY METALS
REINSCH TEST -
dissolve in hydrochloric acid insert copper strip
dark or silvery deposit
confirmatory tests:
1. atomic absorption spectrophotometry
2. emission spectroscopy
3. x-ray diffraction.

FORENSIC SEROLOGY
study of blood - serology
more than 100 different blood factors
possibility classifying each as an individual

ANTIGENS ON RED BLOOD CELLS
ANTIBODIES NATURALLY PRODUCED BLOOD TYPES
ANTIBODIES PRODUCED TO DISPOSE OF SUBSTANCE WITH THE ANTIGENS.
ABO SYSTEM - GENETICS -
GENOTYPES - PHENOTYPES
AA        -     A
AO        -     A
AB        -    AB
BB        -     B
BO        -     B
OO        -     O

RH SYSTEM
D ANTIGEN = +
NO D ANTIGEN = -

WHEN BLOOD MIXED WITH APPROPRIATE SERUM WITH ANTIBODIES THE RED CELLS
 WILL CLUMP.
ANTISERUM (CONTAINS ANTIBODIES) FOR ANY ANTIGEN

BLOODSTAINS-
1st--- Is there blood at the crime scene?
2nd---Is it blood?
3rd ---Is it human blood?
4th--- Whose blood is it?

IS THE STAIN A BLOODSTAIN?
 Color Tests -
     1.Benzidine test
     2.phenolphthalein -
     3. KASTLE-MEYER COLOR TEST
Peroxidase activity - enzymes accelerate oxidation of hydrogen peroxide
    Bloodstain, phenolphthalein reagent and hydrogen peroxide mixed ---deep pink color
Luminol test -
    When sprayed will produce light and stain will glow
     Does destroy some of the diagnostic enzymes

BLOOD SPATTERS
    Examined by a blood spatter expert
    Photographed in detail and mapped into place
Blood spots -
    Shapes by surfaces
    Harder and less porous produce less deformation
    Distortion of blood spot used to determine the angle that the blood traveled from
BLOOD COLLECTION AT SCENE
    All clothing packaged in paper
    If big items cut out stained section
    If cannot collect entire object then--
        1.Scrape off the stain with a clean scalpel onto a clean sheet of paper
        2.Scrape off some unstained portion or cotton swabbed with distilled water---serve as controls
    If wet blood is found---
         1.Should be kept wet
         2.Collect with clean medicine dropper as much blood as possible (also wearing gloves - AIDS)
         3.Put in vial with anticoagulant EDTA and preservative.
1.Photographs of every stain
2.Mapping of the location on drawings
3.Label all samples with keys to the photos and drawings.

IS THE BLOODSTAIN HUMAN OR ANIMAL?
PRECIPITIN TEST
Test tube with human antiserum --pour in extract of blood
If human a white line forms at the interface of the two fluids
Very sensitive requiring only small amount of blood
Used on stains dry for 10-15 years

GEL DIFFUSION
 Antibodies and antigens will attract each other
 Unknown and antiserum in two wells on a starch gel plate
 If human will migrate and form a line of agglutination
ELECTROPHORESIS
 Electrical charge on the plate cause the materials to move
 Reaction with the human antiserum denoted by a line of precipitation
WHOSE BLOOD IS IT?
Blood typing until recently restricted to ABO system
Red blood cells have ruptured.
ABSORPTION-ELUTION TECHNIQUE
1. antiserum of the various blood types added to stain
2. wash off uncombined antiserum
3. break the bond between antibodies and antigen  heating to 56 degrees C.
4. have only antibodies which have combined with antigens on the blood stain
   Mix these antibodies with red blood cells of known types
   Agglutination of the known cells
    Sensitive enough to type a stain
    single fiber one-half inch long
  Stains as old as 11 years
ENZYMES AND PROTEINS
There are a number of enzymes and proteins that occur in polymorphic variants - individuals having different genetically inherited variants or forms of the enzymes.
There are 10 variants of the PGM (phosphoglucomutase) enzyme.
ELECTROPHORESIS
Blood types and enzyme and protein variants can restrict duplication of combined types to a small portion of population
 ----- ie. 0.6 to 0.04%

SECRETORS
About 80% has the secretor gene
Antigens secreted in all body fluids:
  saliva, urine, vaginal secretions, semen
RAPE AND SEXUAL ASSAULT CASES
COLLECTION OF ALL STAINS
    1.Do not fold along stain,
    2.Package in paper
    3.Collect necessary controls of victim and suspect
SEMEN
    Search of the scene, surfaces,sheets and clothing for stains
    Hard white crusty deposits
ACID PHOSPHATASE COLOR TEST
Seminal fluid - acid phosphatase secreted by the prostate gland
        Solution of sodium alphanaphthylphosphate and Fast Blue dye turns purple
        Cauliflower and watermelon, fungi, contraceptive creams and vaginal secretions also contain acid
Phosphatase -speed of the reaction tells if it is seminal fluid.
CONFIRMATION
 Observation of sperm
 P30 PROTEIN unique to seminal fluid
 antiserum in wells of electrophoresis -
 precipitation line indicates presence of p30 and presence of seminal fluid.
RAPE INVESTIGATION
Have victim and suspect disrobe over clean paper on floor to collect any evidence which might fall off.  Collect all clothing being careful not to dislodge stains.  Placed in paper containers.
Victim
1. vaginal swabs
2. oral and anal swabs
3. pubic hair combings
4. head (50) and pubic (25)
    hair controls - pulled
5. saliva sample
6. blood sample
7. finger nail scrapings
8. all clothing

Suspect
1. all clothing
2. pubic hair combings
3. pulled head (50)
   and pubic (25) hairs
4. saliva sample
5. blood sample