Forensic Science

-Debatable

-Is the application of science to those

criminal and civil laws that are enforced

by police agencies in a criminal justice

system.

Important People Mathieu Orfila (1787-1853)-Father of forensic toxicology

-Spanish

-Taught medicine in France

-1814-published a report on the detection of poisons and their effects on animals.

Alphonse Bertillon (1853-1914)-Father of original identification.

-Developed the science of anthropometry-a systematic procedure of taking a series of body measurements as a means of distinguishing an individual from another.

-Replaced by fingerprinting.

Francis Galton (1822-1911) -1st definite study of fingerprints and developed a methodology of classifying them for filing.

-1892-Wrote book on fingerprinting.

Important People Cont.

Leone Lattes (1887-1954) -Discovered the ABO blood typing

-1915-Developed a procedure to determine blood group of dried blood.

Calvin Goddard (1891-1955)-U.S. Army Colonel

-Began the use of comparison microscope to match fired and test fired bullets from a gun--Ballistics

Albert S. Osborn (1858-1946) -Wrote questioned documents (1910)

-Developed the fundamental principles of document examination which was accepted by the courts.

Important People Cont.

Hans Gross (1847-1915)-Prosecutor and judge in Australia

-Spent years developing and studying the principles behind a criminal investigation.

-Incorporated fields of microscopy , chemistry, physics, minerology, zoology, botany, and fingerprinting.

Edmond Locard (1877-1966)

-French

-Developed the “Locard’s Principle”

“With every contact people have, they leave something behind.”

The Scientific Method and The Criminal Investigation

Scientific Method

1- State the problem 2-Form a hypothesis 3-Collect data Observing and

experimenting 4-Interpret the data 5-If data supports

hypothesis, collect more data

6-Draw conclusions

Criminal Investigation -What crime was committed and in what

jurisdiction? -Hypothesize as to possible suspects based

on information gathered from witnesses, physical evidence at the crime scene, and motive (if determined)

-Seek out pertinent records -Review and evaluate the evidence so far

available relative of making a case-for or against each suspect

-Seek additional evidence that will help support and prove your case

-Arrest suspect and continue seeking evidence to support or refute the guilt of defendant

The answer is always there, it is just a matter of asking the right questions.

Crime Scene Physical Evidence: Only and all objects that can establish that a crime has been

committed or can provide a link between a crime and its victim or a crime and its perpetrator.

Types of Evidence

Temporary Conditional Associative Pattern Trace/Transfer -May be -Associated -Links the -Blood -Produced by changed or with specific suspect or -Impressions physical contact can be lost. conditions at victim to the -Tire treads with some surface. the crime scene. scene. -Residues that show the Modus Operandi (how it occurred)

Crime Scene Cont.

Common Examples of Evidence

-Bullets or Firearms -Glass -Fingerprints: visible or latent -Organs -Hair -Paint -Blood, Semen, Saliva -Plastic Bags -Footprints (impressions) -Plastic, Rubber, or other polymers -Documents -Powder Residue (gun) -Drugs -Soil and Minerals

-Explosives -Tool Markings

-Petroleum Products -Vegetative (wood, plants, etc…)

-Serial Numbers

-Fiber: Natural or Synthetic

Crime Scene Cont.

Class Evidence -Evidence that posses

characteristics that can only be associated with as group and never a single source.

Ex) Blood Types

Individual Evidence

-Evidence that can be associated with a common source with extremely high degree of probability

Processing The Scene

Secure and Isolate the Crime Scene -1st officer on the scene -Goal is to preserve and protect to the greatest extent -Only allow authorized people in -Rope and barracades Record the Scene -Limited amount of time at the scene only one shot to find everything. -Don’t want to touch anything. -Photograph the scene scale. -Sketch the scene rough and then final. -Take notes.

Processing The Scene Cont.

Conduct a Systematic Search for Evidence -A search for physical evidence at a crime scene must be thorough and systematic: Spiral Strip or Line Grid Quadrant (Zone)

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Processing The Scene Cont.

Collect and Package Physical Evidence: -The integrity of the evidence is best maintained when the item is kept in its original

condition. -Do this to prevent contamination, breakage, evaporation, accidental damage, or loss. -Each piece will have its own container/bag. Maintain Chain of Custody: -The documentation on the container that shows who is and where the evidence went

from the crime scene to the court house. Obtain Controls: -This is used to match evidence from the scene to an individual or known object. Submit Evidence to the Laboratory: -There are different laboratories under different jurisdictions. Depending on the

investigators and type of crime depends where the evidence was sent.

Processing The Scene Cont.

Henry Lee’s Linkage Principle: Crime Scene Victim Evidence Suspect *You need to be able to argue the case between all four “Air Tight Case”

Product Rule:

-The probability of independent events.

Crime Scene Documentation

-The documentation of a crime scene consists of photographs helps document the facts and physical evidence at the crime scene.

-The crime scene sketch used to plot accurate measurements made at the scene.

-Taking notes Keep a log that records time of discovery of the crime.

Fixed Point Method

Bookshelf

-Door -Window -Wall Corner -Permanent Object -Pick two fixed points -Draw a line from the point to the object.