Fibers Wherever he steps whatever he touches whatever
Fibers “Wherever he steps, whatever he touches, whatever he leaves even unconsciously, will serve as silent witness against him. Not only his fingerprints or his footprints, but his hair, the fibers from his clothes, the glass he breaks, the tool marks he leaves, the paint he scratches, the blood or semen he deposits or collects—all of these and more bear mute witness against him. This is evidence that does not forget. ” —Paul L. Kirk (1902 – 1970) -Forensic scientist Kendall/Hunt Publishing Company
Fibers Students will learn: The student will learn: Chapter 6 § Types of fibers § Why fibers are class evidence. § Distinguish and identify different types of fibers. Kendall/Hunt Publishing Company 1
Fibers " Are fibers class or individual characteristic evidence? " CLASS " Why? " Cannot conclusively link a fiber to one person Chapter 6 Kendall/Hunt Publishing Company 2
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Carpet Fiber Chapter 6 Kendall/Hunt Publishing Company 6
How was he first identified as a suspect? " Surveillance team heard a splash at a bridge and pulled him over Chapter 6 Kendall/Hunt Publishing Company 7
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Other prominent fiber cases "The Roger Payne Case (1968) "The John Serratore Case (1999) Chapter 6 Kendall/Hunt Publishing Company 11
" " " Chapter 6 The Roger Payne Case (1968) The murder of Claire Josephs in Bromley, England, in 1968 was solved in large part through fiber evidence. Her husband found her body. Her throat had been cut, and police discovered that a serrated bread knife was missing from the kitchen. At the time of the murder, she had been wearing a red woolen dress. Lacking evidence of forcible entry and given the presence of a half -empty coffee cup and cookies on the kitchen table, police surmised that the victim knew her killer. Consequently, investigators concentrated on friends and relatives. When they interviewed Roger Payne, a bank clerk who had visited the Josephs’ with his wife earlier that year, they noticed scratch marks on his hands. Analysis of his suit under ultraviolet light revealed 61 red wool fibers that were consistent with those on Claire Josephs's dress. Furthermore, 20 rayon fibers found on Claire Josephs's raincoat hanging inside her front door matched fibers from Payne's scarf, which he had likely hung over her raincoat upon entering the home. In addition, investigators found fibers matching the Josephs's carpet on the floor of Payne's car. The fiber evidence combined with bloodstains in Payne's car that matched Claire Josephs's blood type sealed the case. Payne was convicted and sentenced to life in prison. Kendall/Hunt Publishing Company 12
The John Serratore Case " In June 1999, a New South Wales Supreme Court jury in Sydney, Australia, found John Serratore, 27, guilty of strangling Frances Tizzone, a 21 -year-old student, four years earlier. The two had planned to become engaged before Tizzone broke it off. The verdict was based to a large extent on fibers that were found on the dead woman's shoes. Forensic scientists maintained that these fibers were consistent with fibers from the carpet in Serratore's car. Furthermore, they stated that the fibers would not have remained on her footwear had she taken more than a few steps. Hence the murder must have occurred while she was either in or very near Serratore's automobile. While the evidence could not establish that Serratore was the murderer, it did show that he was at least an accomplice and led to a conviction and a sentence of 20 years in prison " Chapter 6 Kendall/Hunt Publishing Company 13
Fibers § Are considered class evidence § Have probative value § Are common trace evidence at a crime scene § Can be characterized based on comparison of both physical and chemical properties Chapter 6 Kendall/Hunt Publishing Company 14
Fabric § What is fabric? § Fabric is made of fibers. Fibers are made of twisted filaments Chapter 6 Kendall/Hunt Publishing Company 15
§ Types of fibers and fabric § Natural— § animal, vegetable or inorganic § Synthetic— § synthesized or created from altered natural sources Chapter 6 Kendall/Hunt Publishing Company 16
Types of Fibers Synthetic § § § Chapter 6 Natural Rayon Nylon Acetate Acrylic Spandex Polyester § § § Kendall/Hunt Publishing Company Silk Cotton Wool Mohair Cashmere 17
Classification Natural fibers are classified according to their origin: § Vegetable or cellulose § Animal or protein § Mineral Chapter 6 Kendall/Hunt Publishing Company 18
Cellulose Fibers " Cotton—vegetable fiber; strong, tough, flexible, moisture absorbent, not shape retentive Chapter 6 Kendall/Hunt Publishing Company 19
Fiber Comparison Can you tell the difference(s) between the cotton on the left and the rayon on the right? Chapter 6 Kendall/Hunt Publishing Company 20
Protein Fibers § Wool—animal fiber coming most often from sheep, but may be goat (mohair), rabbit (angora), camel, alpaca, llama, vicuna Chapter 6 Kendall/Hunt Publishing Company 21
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Each year Rothschild Road in Emmaville is cleared for the sheep race, the income from which supports the town's museum. Approximately 100 sheep are entered into the one kilometre race. Each wears a coat with a number and the local people pay $5 a head to enter. First prize is $100. " The sheep charge down the street, chased by sheep dogs. Last year was a bit of a spine-tingler, because none of them wanted to cross the finish line. " Chapter 6 Kendall/Hunt Publishing Company 25
Protein Fibers " Silk—insect Silk fiber that is spun by a silk worm to make its cocoon; fiber reflects light and has insulating properties Chapter 6 Kendall/Hunt Publishing Company 26
These little fellas are known as silkworm. Apparently they taste crunchy, oily and yet soft on the inside! Hungry yet? Chapter 6 Kendall/Hunt Publishing Company 27
Mineral Fibers § Asbestos—a natural fiber that has been used in fire-resistant substances Chapter 6 Kendall/Hunt Publishing Company 28
" " " " Chapter 6 joint compound mud and texture coats vinyl floor tiles, sheeting, adhesives roofing tars, felts, siding, and shingles "transite" panels, siding, countertops, and pipes fireproofing caulk gaskets brake pads and shoes clutch plates stage curtains fire blankets interior fire doors fireproof clothing for firefighters thermal pipe insulation Kendall/Hunt Publishing Company 29
§ Rock wool—a manufactured mineral fiber § Rockwool is made by melting a combination of rock and sand then spinning the mixture to make fibers which are formed into different shapes and sizes. The process is very similar to making cotton candy. Chapter 6 Kendall/Hunt Publishing Company 30
"Fiberglass—a manufactured inorganic fiber " Fiberglass is material made from extremely fine fibers of glass Chapter 6 Kendall/Hunt Publishing Company 31
Synthetic Fibers (Made from derivatives of petroleum, coal and natural gas) § Nylon—most durable of man-made fibers; extremely light weight § Polyester—most widely used man-made fiber § Acrylic—provides warmth from a lightweight, soft and resilient fiber § Spandex—extreme elastic properties Chapter 6 Kendall/Hunt Publishing Company 32
Synthetics derived from cellulose " Rayon—chemically-altered cellulose; soft, lustrous, versatile " Cellulose acetate—cellulose chemically-altered to create an entirely new compound not found in nature. Chapter 6 Kendall/Hunt Publishing Company 33
Fabric Production Fabrics are composed of individual threads or yarns, made of fibers, that are knitted, woven, bonded, crocheted, felted, knotted or laminated. Most are either woven or knitted. The degree of stretch, absorbency, water repellence, softness and durability are all individual qualities of the different fabrics. Chapter 6 Kendall/Hunt Publishing Company 34
Weave Terminology § Yarn— § a continuous strand of fibers or filaments, either twisted or not § Blend— § a fabric made up of two or more different types of fiber. Chapter 6 Kendall/Hunt Publishing Company 35
Weave Patterns Chapter 6 Kendall/Hunt Publishing Company 36
Plain Weave § The simplest and most common weave pattern Design resembles a checkerboard Chapter 6 Kendall/Hunt Publishing Company 37
Twill Weave § Makes a diagonal weave pattern § Design resembles stair steps § Denim is one of the most common examples Chapter 6 Kendall/Hunt Publishing Company 38
Satin Weave § The yarn interlacing is not uniform § Creates long floats § Interlacing weave passes over four or more yarns Chapter 6 Kendall/Hunt Publishing Company 39
Knitted Fabric Knitted fabrics are made by interlocking loops into a specific arrangement. It may be one continuous thread or a combination. Either way, the yarn is formed into successive rows of loops and then drawn through another series of loops to make the fabric. Chapter 6 Kendall/Hunt Publishing Company 40
Polymers § Synthetic fibers are made of polymers which are long chains of repeating chemical units. § The word polymer means many (poly), units (mer). § The repeating units of a polymer are called monomers. § By varying the chemical structure of the monomers or by varying the way they are joined together, polymers are created that have different properties. § As a result of these differences, forensically they can be distinguished from one another. Chapter 6 Kendall/Hunt Publishing Company 41
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Filament Cross-Sections Synthetic fibers are forced out of a nozzle when they are hot, and then they are woven. The holes of the nozzle are not necessarily round; therefore, the fiber filament may have a unique shape in cross-section. Chapter 6 Kendall/Hunt Publishing Company 43
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