End of the Year Project

Berenice Rosas 2nd period

Standard 3

Explain Locard's Exchange Principle:


  • concept that was developed by Dr. Edmond Locard (1877-1966).
  • every time you make contact with another person, place, or thing, you exchange of physical materials.
  • no matter where a criminal goes or what a criminal does, by coming into contact with things, a criminal can leave all sorts of evidence,
  • this included DNA, fingerprints, footprints, hair, skin cells, blood, bodily fluids, pieces of clothing, fibers and more.
  • At the same time, they will also take something away from the scene with them. Categorize the different types of evidence
  • Testimonial evidence: also known as a testimony, which consists of statements that are made in court by witnesses, that are offered as proof of the matter asserted, or of what is being discussed.
  • Physical evidence: Physical evidence usually involves objects found at the scene of a crime, such as objects, prints such as fingerprints, footprints, hand prints, tidemarks, cut marks, tool marks, etc.
  • Individual evidence: characteristics that can be identified as having originated with a particular person or source.
  • Class evidence: A group of objects or persons with characteristics physical evidence common to it.

Standard 4

Explain the process of performing an autopsy:

  • An autopsy is taken place to determine the cause of death.

An autopsy takes the form of six stages

  • Y-incision
  • Removal of Organs
  • Stomach Contents
  • Sample Collection
  • Head and Brain examination
  • Conclusion

Research PMI (Post Mortem Interval)

  • PMI is the time that has elapsed since a person has died
  • Before death: ante-mortem
  • Moment of death: agonal period
  • After death: post-mortem

After 24 hours

  • Body temperature is equal to environmental.
  • The head and neck are now a greenish-blue color, that spread over the whole body.
  • There starts to be a strong smell of rotting meat.
  • The face of the person is essentially no longer recognizable.


  1. Livor Mortis: The discoloration of the body after death due to the gravitational setting of blood, 30 mins after death, the skin gets purple and waxy, the hands and feet turn blue, the eye starts to sink into the skull.
  2. Rigor Mortis: the whole body becomes completely rigid after about 12 hours, It is affected by environment, sex, age, and cause of death.
  3. Algor Mortis: coldness of death, Temperatures drops depends on many factors and its less reliable for determination of PMI.

Standard 9

Explain how forensic science is used in the courtroom:

  • Linking weapons to crime scenes
  • Proving where and when bullets were fired
  • Analyzing crime scenes
  • Finger print identification
  • Identifying residue in crime scenes
  • Providing validated factual physical evidence
  • Creating a scenery to the crime
  • Validating further information in court
  • Tracing weapons to their suppliers and owners
  • Sanction off material to be presented as evidence in court
  • Tracing teeth to its owner
  • Connecting fabric to a crime
  • Allowing the bite marks to to be used for linking a criminal to a crime
  • Linking hair samples to an exact suspect
  • The ability to prove the owner of a collected saliva sample