Science evidence and investigation

• FBI began the fingerprint file in 1930
• Basic fingerprint patterns are

  • Arch
  • Whorl
  • Loop
• When the Police identify fingerprints, they look at the pattern the print
• In order for it to be a match, they have to have multiple ridges in common
• Soil

  • Has hummus
  • Fur / hair
• The colour of soil indicates the material the soil is made of
• Soil with little to no humus is lighter
• Soil with larger particles


  Rougher and grittier
• Police compare soil samples found at the scene of a crime with what's found on suspects clothes, in their car and in the treads of tires
• Plant-based fabrics will ignite easily
• Wool and silk don't burn easily, works away from fire
• Possible fabric tests


  • Water test - how well it holds colour in wash?
  • Burn test - does it melt?
• Manipulated variable is the thing being changed
• • The length
  • The tread
  • The direction
  • The grooves
  • Are all characteristics of tires