Soil Flashcards
What is Forensic Geology?
- application of the geological information and techniques to problems that may come before a court of law
What is Forensic Soil Science? (also forensic pedology)
- application of information relating to the properties of soils in matters that may come before a court of law
Trace evidence is governed by what principle?
Locard Exchange Principle
What other evidence uses the sediments and soils as matrices?
- human remains
- non-soil trace evidence (hair, fibers, ignitable liquid residues, explosive residues)
What is the Locard Exchange Principle?
- every touch leaves a trace
- holds that the perpetrator of a crime will bring something into the crime scene and leave with something from it, and that both can be used as forensic evidence
- there is a triangle between victim, perpetrator, and crime scene
What are the limitations to the Locard Exchange Principle
- not all trace evidence is transferred
- not all transferred trace evidence is retained
- not all transferred trace evidence is recovered
- trace evidence may be transferred without direct contact
What are some methods that is used at the CS to collect trace evidence?
- hand picking
- taping
- adhesive lifters
- vacuuming
What are some precautions that investigators must remember when collecting evidence at the CS?
- must take care not to leave their own trace evidence at the scene
- items of evidence must be handled and packaged to minimize redistribution of trace evidence and to prevent cross-contamination
What are some methods used in the lab when collecting trace evidence?
- hand picking
- scraping
- taping
- adhesive lifters
- vacuuming
What are some precautions that technicians must remember when collecting evidence in the lab?
- only one item of evidence should be examined at a time
- a special clean room should be used for examinations
- work surfaces should be thoroughly cleaned after the examination of each item of evidence
What are some types of geological and soil materials that may appear as Forensic Evidence?
- rocks
- sediments
- soils
- dusts and particulates
- minerals
- glasses and other amorphous materials
- fossils
- anthropogenic materials
What are the three main types of rocks?
- igneous
- metamorphic
- sedimentary
Igneous Rocks
- formed by crystallization from molten magma
- below Earth’s surface (intrusive or plutonic)
- at the surface (extrusive or volcanic)
Metamorphic Rocks
- formed from a pre-existing rock or sediment
- there are changes in mineralogy, chem & structure
- these are subjected to high temps, pressure &/or sheering
What are the types of metamorphism
- burial
- contact
- shock
