Forensic Analysis Flashcards
Name some forms of physical evidence
- Documents
- Glass
- Soil/wood
- Finger prints/other impressions
- Hair fibres
- Fire arms/ammo
- DNA
- Powder residue
- Explosives and propellants
- Drugs
- Paint
- Bodily fluid
- Blood
How could documents be tested?
Chromatography of suspect’s pen can be associated/excluded with pen found at crime scene.
Can be tested if it does/doesn’t contain fluoresce.
How could glass be tested?
Analysis of Refractive Index (RI=sinR/sinI) can be compared and associated/excluded from crime scene.
Analysed to find fluids from suspect.
Angle of impact can be found.
How could soil be tested?
pH testing reveals how much hydrogen is in the soil and therefore, how acidic it is.
It can show where the person has been.
How could fingerprints be tested?
- Magnetic powder.
- superglue fumes.
- Ninhydrin.
- Iodine Crystals.
- Carbon powder.
How could hair fibres be tested?
Analysed under microscope and associated/excluded.
How could DNA be tested?
Gel electrophoresis used to compare suspect’s DNA with DNA found at crime scene.
How could powder residue be tested?
If if has fluroescent substances, it will be revealed under UV lights.
Many times will be related to firearms/explosives
How could shoe prints and impressions be tested?
Shaped using Plaster of Paris, Analyse and compare prints
How can bodily fluid be tested?
UV lights used to find fluids.
How can blood be tested?
- Blood typing is performed (ABO, Rh)
- Blood splatter used to find angle of impact, point of origin and weapon used.
What is the term used when comparing pieces of evidence?
Exclusion vs Association
What is a Control Sample?
Well known Forensic sample used to assure analyses are properly performed so that results are reliable.
