Damage to Textile Flashcards
What is the usefulness of damage analysis?
Depends on recognition by the police investigator and subsequently the forensic scientist that it could provide valuable evidence.
Types of cases where damage analysis could be invaluable?
homicide or suicide
rape
sexual assault
armed robbery.
Three broad categories of events may cause damage to textiles?
mechanical effects,
chemical effects and
the influence of heat.
What is a tear?
A severance caused by the pulling apart of a material, leaving ragged or irregular edges.
What is a cut?
A severance with neat edges produced by a sharp-edged instrument.
Types of cut
- Stab Cut
- Scissor Cut
- Slash Cut
- Abrasion
- Puncture
What weapon causes stab cut?
Knives
What weapons causes slash cuts?
Sharp edged tool like knives, blades and scalpel
What is a puncture?
Penetration through material by an implement producing an irregular hole.
What causes abrasive damage?
Material rubbing against another surface.
What is tensile failure?
Fracture of the textile through pressure, especially in ropes.
What is animal damage?
These are damages caused by bitemarks produced from jaws or feet or when insects may ingest fibres creating puncture holes.
What is microbial damage?
This is irregular damage to material, most often seen in burials. Microbes such as bacteria and fungi may destroy fibres.
What fibres may be affected by microbial damage?
Natural fibres
What are tearing indications?
- Damage follows preferred direction of tear- i.e. parallel to the warp or weft.
- Associated stretching
- Edges devoid of ‘planar array’
- Noticeable ‘curling over’ of the fabric along the severance line.
What are cutting indicators?
1.No preferred direction.
2. Relatively featureless edges.
3. An ability to fibre-end or pattern match.
4. Presence of a significant ‘planar array’.
How can an examiner know if the garmet has been washed?
Matted and tangled fibres at the ends of cut yarns
Parts of the three level fibre examination?
- Fabric Level
- Yarn Level
- Fibre Level
What interpretation can be made from simulation?
- the determination of the type of damage
- the class of the weapon used and if the source of damage was by said weapon
What are four variables which are unknown or cannot be replicated in attempting to simulate?
- the body weight and type of the individuals involved,
- their movement
- the angle and type of thrust
- position of the clothing.
What are limitation in simulation scenario?
When more damage may occur after the offence has happened such as cutting off the garmet at the hospital.
