TRACE EVIDENCE :
HOW CAN IT BE CLASSIFIED :
2 categories: Physical and Chemical
Differentes pieces: pointer,ocular,stage clip,arm,coarse adjustement,fine adjustement,body tube,nose piece,objectives,stage,illuminator.
DETERMINING THE SIZE OF AN ORGANISM :
1.We must first know the size of the diameter of our field vision.(for each possible total magnification)2.Magnification: Diameter of field:
( - - - - - - - - - - ) ex: the cell is only taking 2 off 10 2/10 of the scale. Which means its 0.2
The diameter of field used was 1750.
You do: 0.2x1750= ANSWER
HAIR LAB 5#:
Root: make the difference between human andnon-human hair.
MEDULLA ET AUTRES :
• Absent,fragmented,intermittent and continuous. (different patterns
• IS THE CENTRAL CORE
• Determine color hair (CORtex=COLor)
• Contain melanin
• Largest portion of the hair
• Made up of dead,translucent cells STRENGTH OF THE HAIR
• Coronal,spinous or imbricate
HUMAN VS ANIMALS:HUMAN:
HAIR TYPES: facial,limb,pubic ETC
SCALE PATTERN:spinous,coronal et imbricate.
HAIR TYPES : guard hair(outer coat)
Ground hair (underfur)
Tactile hair (whiskers.)
THESE ARE UNIQUES CARACTERISTICS WHICH HELP A LOT SCIENTIST IN THEIR RESEARCH!!
• It is impossible to perfectlylink hair samples to an individual.
• Class evidence
!ONLY WAY IS IF IT CONTAINS DNA. FOLLICULAR TAG!
MAKING A MATCH:
1.having +/- 50 hairs from the suspect
2.compare by looking at:
2 CATEGORIES: NATURAL AND MANMADE
CARACTERISTICS TO TAKE CARE OF:
Fiber type shapediameter color variation of color in the fiber
Length of fiber lengthwise striations of the fibers surface
• Should be collected as soon as possible if not they may be lost
• Fibers are collecting by TAPING or by VACUUMING
• ANALYZED BY: diameter,shape,color,shininess,curls and crimps
• USED TOOLS:Birefringence: for synthetic fibers
Microspectrophotometry: determines a fibers true color
Polarized light: reflective index
Refractive index: refractive index
Scanning electron microscope: fine structural and surface details of damaged fibers
!ANALYSE CHEMICAL AND PHYSICAL CARACTERISTICS!!
• All glass can be different
•Broken glass provide information like:
-point of entry/exit
-what broke it
SOILS AND PLANTS:
-Since plants grow in different areas, it decreases the size of a search of that specificacity
-how blood moves and behaves under the laws of physics
-how blood behaves chemically
-molecular component found inside theblood
1)blood under laws of physics:
- will land in specific pattern :: velocity,size,angle WHEN DROPPING
PROVIDE GOOD ANSWERS TO QUESTIONS LIKE:
; Where did the blood come from
; What object caused the victim to bleed
; What direction did the object strike the victim from
; Where did the victim and assailant start,and where did they move to?
; How many strikes?( combien de coupures ?)2)blood chemicals
-Special proteins in the blood creates des caillots (clots) once it leaves the body
MORE TIME = MORE CLOTTING
Still liquid( minutes have passed
Jelly-shiny substance( up to an hour has passed
Separated into clot and serum( more than one hour has passed
3) Molecular component:
-Cells; DNA which is unique to every person
-Drugs,poisons and alcohol can also...
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