Forensic Science: Hairs & Fibers Overview

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Questions and Answers

What type of evidence can be transferred when two objects come into contact?

Metals and plastics

Hairs and fibers (correct)

Glass and ceramics

Documents and photographs

Which of the following is not a type of fiber identified in forensic examinations?

Acrylic

Polyester

Silk

Granite (correct)

What assessment is performed to determine if hairs are of human or animal origin?

Optical property analysis

Chemical analysis

Physical examination

Microscopic evaluation (correct)

Which method is utilized for nuclear DNA testing on human hairs?

PCR-based typing Signup and view all the answers

In forensic investigations, which location is least likely to be a source of hairs and fibers?

Neighbors' yards Signup and view all the answers

What is the first step in comparing questioned fibers to known samples?

Color identification Signup and view all the answers

Which of the following does not fall under the capabilities of trace evidence analysis?

Identification of hair color Signup and view all the answers

What properties may be compared between known and questioned fibers?

Optical properties Signup and view all the answers

What should be avoided when collecting hairs and/or fibers?

Packaging in high tack adhesive tape Signup and view all the answers

What is the preferred method for collecting very small hairs and fibers?

Using a low tack adhesive note Signup and view all the answers

When collecting clothing, what should the individual stand on?

Clean butcher paper Signup and view all the answers

How should individual hairs and fibers from clothing be packaged?

In a paper evidence fold and included with the clothing item Signup and view all the answers

What is a suitable way to package collected evidence?

Using a low tack adhesive note before sealing in an envelope Signup and view all the answers

Why should high tack adhesive tapes be avoided?

They make recovery of hairs and/or fibers difficult Signup and view all the answers

What is the correct order of operations when removing clothing for evidence collection?

Remove one article at a time onto butcher paper Signup and view all the answers

In packaging evidence from clothing, what should each clothing item be placed into?

A separate paper bag Signup and view all the answers

What should be done if a subject’s clothing has been bagged together?

Leave the clothing items combined and submit them as one. Signup and view all the answers

What method is suggested for submitting large items such as area rugs or vehicle seats?

Recover fibers using low tack tape before submission. Signup and view all the answers

What is the preferred wrapping method for items submitted for lab analysis?

Wrap in paper and place into a paper bag. Signup and view all the answers

When submitting known hair samples, which agency can perform further examinations?

The FBI. Signup and view all the answers

What type of tape is recommended for fiber recovery from large items?

Low tack tape. Signup and view all the answers

What should be done with a known fabric sample when full items cannot be submitted?

Submit a smaller fabric piece that includes all colors and types. Signup and view all the answers

How should recovered tape strips with fibers be submitted?

Placed on a clear plastic sheet or into a plastic bag. Signup and view all the answers

What is the purpose of collecting known hair samples?

For potential future microscopic comparisons. Signup and view all the answers

Study Notes

Trace Evidence: Hairs & Fibers Overview

Hairs and fibers can be transferred when objects come into contact.
Hairs are assessed to determine if they are animal or human.
Human hairs are categorized by their suitability for nuclear DNA testing.
Fibers are identified by color, generic type (e.g., nylon, polyester, acrylic), and compared to samples from known sources.

Capabilities and Services

Distinguish hairs from fibers.
Differentiate human hairs from animal hairs.
Determine the suitability of hairs for nuclear DNA PCR-based typing.
Fracture match rope/cordage or clothing/fabrics.
Identify fiber generic class (e.g., nylon, polyester, cotton, silk, wool).
Compare questioned fibers to known fiber samples.

Collection Guidelines: Individual Hairs and/or Fibers

Use forceps or gloved fingers to remove hairs and/or fibers.
Package hairs and/or fibers in a properly folded paper evidence fold, a glassine envelope, or on the adhesive edge of a low tack adhesive note.
Small hairs and/or fibers are best collected with a low tack adhesive note.
Do not crush, bend, or use high tack adhesive tapes to recover hairs and/or fibers.

Collection Guidelines: Clothing

Remove and package each clothing item separately.
Use new, clean pieces of butcher paper to avoid contamination.
Package individual hairs and/or fibers recovered from the clothing item with the clothing item.
Do not separate clothing items if they were previously bagged together or placed in one pile.

Collection Guidelines: Large Items

Submit items for lab examination whenever possible.
Use low tack tape with clear/colorless backing and adhesive to recover hairs and/or fibers from large items.
Alternatively, use painter’s masking tape for collection.
Place taped strips with recovered hairs and/or fibers onto a clear/colorless plastic sheet, transparency sheet, or plastic bag.

Collection Guidelines: Known Samples

Collect known hairs for potential future microscopic hair comparisons (not conducted by DFS).
Submit entire fabric items when possible, or a representative sample that includes all colors and types of fibers.

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Description

Explore the critical role of hairs and fibers in forensic science through this quiz. Learn how to distinguish between human and animal hairs, as well as how to identify various fiber types. Test your knowledge on collection guidelines and the methodologies used in forensic analysis.