Chapter 5 Flashcards
It is one of the oldest forms of physical evidence.
Hair examination
Its use is older than fingerprints. It is valuable because the hair of each kind of animal is different and distinct for all others.
Hair examination
In _____, hair examination was first used as physical evidence.
1847
In _____, Rudolph Virchow become the first person to do an in-depth study of hair.
1897
In _____, Hugo Marx wrote a paper on the use of hair in forensic investigation to determine identity.
1906
In _____, Dr. Paul Kirk works on new ways to improve the use of hair in forensic investigations.
1931
_____________ at the crime scene must be done. Use ____________.
Complete search, vacuum cleaner
All of the hair in the questioned specimens should be ________ but do not ____ hairs at different places.
submitted, mix
________ for and _________ of hair evidence should begin as soon as possible. Hair evidence is easily transferred to and from the crime scene.
Search, collection
Collection should be done by?
a) Hand, if the location of the hair is important;
b) Lint rollers; or
c) Special filtered vacuum cleaner – collects hairs and fibers in mass from carpet, bedding, etc.
It collects hairs and fibers in mass from carpet, bedding, etc.
Special filtered vacuum cleaner
If the evidence is ______ to another object, the entire object should be packaged and labeled (Corpuz, 2015).
stick
If lint rollers are used, the entire surface used should be packed into a ______________________ (Corpuz, 2015).
polyethylene storage bag
In vicious assault and murder cases, obtain the _________ of the victim from the hospital or morgue to avoid the loss of evidence by careless handling and to prevent the clothing from being destroyed.
clothing
_____________________________ from the victim as well as the suspect should be obtained if possible.
Representative samples of hair
To be a representative head hair samples from a particular individual, it should consist of at least a ________ hairs from different areas of the scalp and preferably ___________ hair.
dozen, full-length
Take from all pertinent regions of the body:
a) 50 head hairs;
b) 24 pubic hairs (Corpuz, 2015).
Don’t ______ known samples of hair from different parts of the body.
mix
Hair evidence should be looked for in the following:
clothing, combs, weapons, pockets, fingers, hat and etc.
Get samples from both _______ and ________ (dead body: head hair and pubic hair). It should be taken before it is buried.
victim, suspect
Best way to collect hair is by ________.
combing
Hair evidence should be packaged into ___________.
paper packets
The hairs should be placed in a ____________ or in a _________________, but the corners of the envelope should be sealed with ___________.
folded paper, white mailing envelope, scotch tape
Do not secure the hair samples to a piece of paper with ________ because this will damage the hair.
scotch
All __________________ should be removed from the submitted specimen.
foreign fibrous debris
__________________ or _________________ are not suitable for examination.
Fragmentary hairs, underdeveloped hairs
Areas on an object containing hairs should be protected with ____________ or ________ taped over the area before wrapping the object from transmittal to laboratory.
cellophane, paper
Methods of packing hair
pill box or test tube
Questioned specimens
druggist powder papers
This refers to a specialized ephitilial outgrowth of the skin which occur everywhere on the human body except on the palm of the hands and the sole of the feet.
Hair
It is an appendage of the skin.
Hair
Hair is not completely ______ but may be _____or _________.
round, oval, flattened
Two Kinds of Hair (among mammals including human being)
- Real Hair
- Fuzz Hair
It refers generally to long and stiff hair.
Real Hair
It refers generally to short, fine at times curly and wooly hair.
Fuzz Hair
Parts of the Hair
- Root
- Shaft
- Tip
It refers to portion of embedded in the skin.
Root
It refers to portion above the surface of the skin. It is the most distinctive part of the hair.
Shaft
It refers to distal end of an uncut hair shaft. It is refers sometimes to point.
Tip
Parts of the Shaft
- Cuticle
- Cortex
- Medulla or Core
It refers to the outermost covering of the hair. It is consists of one layer of non-nucleated polygonal cells which overlaps like the scales on fish.
Cuticle
It refers to the intermediate and the thickest layer of the shaft and is compose of elongated, spindle shaped fibrils which cohere. They contain pigment granules in varying proportion depending on the type of the hair.
Cortex
It refers to the central canal of the hair that may be empty or may contain various sorts of cells more or less pigmented and begins more or less near the root.
Medulla/Core
Certain hair has medulla. Therefore hair can be classified into two categories namely:
a) Hair without medulla
b) Hair with medulla
It can be interrupted, continuous, fragmented, solid or none/absent.
Medulla
Hair should be cleaned with a mixture of equal parts of _______________.
alcohol and ether
It can be examine using the naked eye or under the microscope.
Color
It refers to the brownish-black pigment in the hair, skin, etc. It is the chemical responsible for the color of the hair. Black and brown hair differs only on the amount of melanin. Red hair is thought to be due to iron.
Melanin
Tip of the hair may show whether a hair has been cut. Tips of body hair become rounded from rubbing against the cloths. Hair of human usually shows a fine tip. Men’s hair tip is apt to be cutoff square.
Character of the hair tip if present
It may show whether a hair has been cut.
Tip of the hair
The size, the general shape and the irregularity of the scales are observed.
Character of cuticle
Structural features is studied under the microscope.
Character of cortex
It is embedded with the pigment granules that impart hair with color. It is the color, shape and distribution of these granules that provides the criminalist with important points of comparison between the hairs of the different individuals.
Cortex
Dyed hair can be distinguished from natural hair. Under the microscope dyed hair has a dull appearance and the color tone is constant, whereas natural is not and the individual pigment granules stand shapelier.
Presence of dye in hair
It refers to the innermost layer of your hair. It consists of a soft, thin core of transparent cells and air spaces (Kingsley, 2016).
Medulla
These are the most characteristic portion of the hair.
Medulla and Cortex
This refers to the relationship between the diameter of the medulla and the diameter of the whole hair usually expressed in fraction. Its determination is performed under a microscope provided with micrometer eyepiece.
Medullar Index (M.I.)
Hair with narrow medulla belongs to human and certain monkey hair.
less than 0.5
Hair with medulla belongs to hair of cow, horse and others.
approximately 0.5
Hair with thick medulla almost all animals belong to this.
greater than 0.5
Based on the ___________________, it can be determined whether hair is human or animal origin.
medulla examination
In most instances, it can be determined whether a human hair came from Negroid, Mongoloid or Caucasian race.
Determination of characteristics by race
o Contains heavy pigment distributed unevenly
o A thin cross section
o Hair is usually kinky with marked variation in the diameter along the shaft.
Negroid Race Hair
o Hair contains dense pigment distributed more evenly than Negroid race hair.
o Cross section of the hair will be round to oval in shape.
o Hair is coarse and straight with very little variation in diameter along the shaft of the hair.
o Usually contains a heavy black medulla or core
Mongoloid Race Hair
o Hair contains very fine to coarse pigment and more evenly distributed than is found in Negro or Mongolian.
o Cross section will be oval to round in shape.
o Usually straight or wavy and not kinky
Caucasian Race Hair
These are more mature than any other kind of human hair.
Scalp Hair
This is coarse, curve, very stiff and often triangular in cross section.
Beard Hair
This is usually triangular in shape and very stiff.
Moustache
These are short stubby and have wide medulla.
Hairs from eyebrows, eyelid, nose and ear
These vary in thickness along the shaft and are immature but are somewhat similar to head hairs. They have fine, long tip ends.
Trunk Hair
These are similar trunk hairs but usually are not so long or so coarse and usually contain less pigment.
Limb Hair
These are fairly long with unevenly distributed pigment. They vary considerably in diameter along the shaft and have frequently a bleached appearance. It has an irregular shape and structure. Looks like pubic hair but the ends are sharper and the hair is not so curly.
Axillary Hair
These are similar to axillary hairs but are coarser and do not appear bleached. Wirier, have more constriction and twists and usually have continuous broad medulla. Have many broken ends because the clothing rubs off against it.
Pubic Hair
a) Identification of questioned hair
b) Comparison of questioned and known hair
Light Microscopy
Link the suspect to a crime scene. Control hairs match that of the suspect. Exclude the suspect from a crime scene, meaning that a control hair does not match the evidential hair.
Comparison Microscope
Determine the species, race, and somatic origin of a hair.
Scanning Electron Microscope (SEM)
This is to test and determine whether a drug was used.
Drug Test
Hair strands normally grow at an average rate of _______________ every month; they absorb metabolized drugs that are fed to the hair follicle through the blood stream.
1.3 centimeters
Two Assays Used in Forensic
- Radioimmunoassay (RIA)
- Enzyme-Linked Immunosorbent Assay (ELISA)
The word “textile” is derived from the Latin word _________ and the French _________, __________, hence fiber means that can be converted into yarn.
“textillis,” “textere,” to weave
Types of Textile Fibers
- Natural Fibers
- Man-Made Fibers
Test for Textile Fibers
- Burning or Ignition Test
- Fluorescent Test
- Microscopic Examination
- Chemical Analysis of Fibers
It is a preliminary macroscopic examination. A test that determines whether fiber is mineral, animal or vegatble fiber.
Burning or Ignition Test
These fibers smolder or burn slowly and give odor like that of burning feather. When removed from the flame they do not continue to burn readily and a charred bead remains at the end of the fiber. Fumes turn red litmus blue.
Animals’ fibers
This is odor strong, disagreeable; fumes turn lead acetate paper black or brown.
Wool
Its odor is not so pungent, fumes have no effect on lead acetate paper.
Silk
These fibers burn rapidly with a flame and give off but little smoke or fumes. Charred bead not present when fiber is removed from the flame. Fumes turn blue litmus red.
vegetable fibers
It is frequently used to determine the general group to which a fiber belongs. It is not reliable for positive identification of fibers. In general, the vegetables fibers exhibit a yellow fluorescence in ultra-violet light, whereas the animal fibers show bluish fluorescence.
Fluorescent Test
In general, it is the most reliable and best means identifying fiber. The fiber is placed on a glass slide, teased and covered.
Microscopic Examination
This is an unicellular filament, flat, ribbon-like, twisted spirally to right or left on its axis, central canal or lumen broad uniform in diameter; cell wall thick, covered by a thin, structureless, waxy cuticle. Fiber tapers gradually to a blunt or rounded point at one end.
Cotton
This is straight, cylindrical, with occasional twists; evenly lustrous, smooth except for occasional transverse folds or wrinkles. Cuticle mostly lacking, lumen irregular in width.
Mercerized Cotton
This is a multicellular filament, straight and cylindrical, not twisted and flattened, tapering to a sharp point. Cell wall thick, the lumen appearing as a narrow dark line in the center of the fiber. Filament marked by transverse lines at intervals causing fiber to appear jointed, resembling bamboo. Cross lines frequently interest appearing like the letter x.
Linen
This is smooth, cylindrical, lustrous threads, usually single but often double, the twin – filaments held together by an envelope of gum. More or less transparent, without definite structure.
Cultivated Silk
This is similar to cultivated silk but broader and less regular in outline. Marked by very fine longitudinal striations with infrequent diagonal cross-markings.
Wild Silk
This is a cylindrical, lustrous, appearing like a glass rod. Microchemical reactions, dissolved rapidly by half saturated chromic acid; not colored by Millon’s reagent as in case of true silk.
Artificial Silk
This is easily distinguished by presence of flattened, over lapping epidermal scales not found on silk or any of the vegetable fibers. Fiber many – celled, cylindrical; shaft composed of three layers; central core or medulla (seldom seen), cortex and scaly cuticle.
Wool
If the sample submitted for analysis is fairly large, such as a piece of cloth or a number or large threads, it is suggested that a chemical analysis be made to supplement the microscopic examination and confirm the results obtained form that procedure.
Chemical Analysis of Fibers
In this test, the fiber is stained with picric acid, Millon’s reagent, stannic chloride or iodine solution.
Staining Test
If the fiber is white or light colored it is treated with the following chemicals. If dyed, the fiber is first decolorized by boiling in ether 1% hydrochloric acid, acetic acid or dilute potassium hydroxide.
Dissolution Test
