Introduction to Forensic Science

• Science used in legal investigations
• Forensic science as a field encompasses Chemistry, Biology, Physics, Computer science, Medicine, Pharmacology, Anthropology/Archaeology, Marine science, Psychology.
• Forensic science sits at the intersection of science and the law.

What Forensic Science is Not

• Forensic science is not accurately portrayed in prime-time television shows like CSI, which have increased public awareness but created unrealistic expectations.
• Real forensic procedure can take days, weeks or even years, while on TV it only takes minutes.
• Not every crime scene yields forensic evidence that supports a case.
• The "CSI effect" is the unrealistic expectation that a prosecutor's case should be bolstered by forensic evidence.
• Jurors place a lot of weight on forensic evidence.

History of Forensic Science

• Pre-700 B.C.: Fingerprints were used on clay tablets for business transactions in ancient Babylon.
• 287-212 B.C.: Archimedes discussed how to prove a crown was not made of gold using density and buoyancy.
• 1235-1248 A.D.: Sung Tz'u's "The Washing Away of Wrongs" was released, marking the first recorded application of medicine for solving crimes.
• 1447 A.D.: Charles the Bold's missing teeth were used to identify his remains.
• 1590 A.D.: The first optical microscope was developed.
• Mid-19th Century is when forensic science begun to coalesce as a recognized discipline.

Key People in Forensic Science History

• Key people in the field of forensic science include Victor Balthazard, Alphonse Bertillon, Sir Francis Galton, Calvin Goddard, Hans Gross, Edmond Locard, and Mathieu Orfila.
• Most of these figures were generalists rather than specialists.
• Victor Balthazard (1852–1950): A French medical examiner who advanced fingerprint, firearm, and hair analysis in Paris.
• Victor Balthazard developed probability models for fingerprints and photographic methods for comparing bullet markings and wrote "The Hair of Man and Animals" first comprehensive book on hair analysis.
• Alphonse Bertillon (1853–1914): A French developed the first systematic method for identifying suspects and criminals called Anthropometry or Bertillonage.
• Anthropometry was based on 11 body measurements, descriptive information, and photographs, though fingerprints were not initially collected.
• Anthropometry was commonly used from 1883 to the early 1900s.
• Sir Francis Galton (1822–1911): An English who created the first classification system for fingerprints, with basic patterns like loop, arch, and whorl.
• Sir Francis Galton published "Finger Prints" in 1892, bringing fingerprinting to the forefront of criminal identification.
• Still considered a primary reference in the field
• Dr. Edmond Locard (1877–1966): A French with training in law and medicine, established a forensic laboratory in Lyon, France.
• Dr. Edmond Locard was interested in microscopic and trace evidence and believed it was crucial in linking people to places
• Dr. Edmond Locard is most famous for Locard's Exchange Principle usually paraphrased as "every contact leaves a trace".

Science and the Law Today

• Law settles disputes between individuals/the state (criminal law) or among individuals/entities (civil law).
• The law is guided by precedent and functions using an adversarial system.
• In a legal context, there are two opposing sides arguing for acceptance.
• Legal proceedings are outcome-based.
• The finder of fact or trier of fact, typically a judge or jury, determines the truth based on evidence presented by opposing sides.
• Science enables us to ask basic questions about the natural world, such as how the Earth formed and what governs the property of matter.
• Science helps answer questions using observation, testing, and interpretation through logic and scientific method.
• A good forensic scientist practices good science.

Scientific Definitions

• Hypothesis: A tentative explanation for an observation, phenomenon, or scientific problem that can be tested by further investigation.
• Scientific theory: An explanation of some aspect of the natural world that has been substantiated through repeated experiments or testing.
• Fact: A confirmed or agreed-upon empirical observation or conclusion, or knowledge based on real occurrences, not just a hunch or guess.
• The scientific theory that explains evolution is known as 'natural selection'.
• Darwin's theory explains that evolution has yet to be falsified, predicts nature.

How Science Works

• The core logic of science involves testing ideas with evidence.
• The scientific method is a framework for conducting research, often oversimplified like a recipe.
• The process of science is not linear.
• The process of science is iterative, circles back so that useful ideas are built upon other ideas.
• In any point of the process leads to many possible "next steps".
• Science depends on interactions within the scientific community and different parts of the process may be carried out by different people at different times
• The single scientist in a dark cellar is a thing of the past; team work is key.
• Team-work includes Crime Scene investigator (CSI), Scene of Crime Officers (SOCO), Forensic Identification Officer, and Forensic Scientists (specialists).
• Science is exciting, dynamic, and unpredictable that relies on creative people thinking outside the box
• Science should have no distinction between the "hard" and "soft" sciences and it should use good creative problem solving and solid methodology.
• Scientific conclusions are always revisable if warranted by the evidence, because science is falsifiable.
• Most scientists agree that science leads to an understanding of what is most likely to be correct at the current time with the available evidence.

Legal Proceedings

• Modern forensic science practice has been classified in legal proceedings
• The role of the forensic scientist is not concerned with the truth but only about the evidence.
• Forensic scientists will examine proper evidence collection, identifying the evidence, contamination issues, proper documentation, and clear communication of ideas.
• Training and education include the CSI, Forensic Scientists, Public laboratories, and Private laboratories.
• The training for CSI is police officers, general patrol, post-secondary education, SOCO police academies, forensic identification unit, and it is multi-disciplinary.
• Forensic Scientists training include scientists, technicians, undergraduate, postgraduate, based in laboratories or universities and it is a one discipline study.
• Public laboratories are generally government-funded, and private laboratories are designed to make a profit.
• Private laboratories mostly work with DNA and forensic toxicology.
• Forensic scientists work with, Biology, Chemistry, Toxicology, Documents, Firearms and Toolmarks, and Electronics

Academic Forensics

• Academic forensics include teaching science, mock crime scenes, curriculum development, and research.
• Types of legal proceedings include criminal and civil court proceedings.
• Criminal cases involve government and individual, or a violation of criminal laws such as Felony or Misdemeanor where guilty must be proven beyond a reasonable doubt (99%).
• Civil cases involve individuals and a "Lawsuit" or "being sued" such as patent infringements, where preponderance of evidence must be proven (51%).
• Jurisdictions have different legal rules and procedures such as local, state, federal, etc.
• Roles inside Legal Proceedings are trier and Finder-of-fact, Prosecution and Plaintiff, and a Defendant.
• The Prosecution bears the burden of proving a defendant guilty beyond reasonable doubt.
• Plaintiff proves the case by preponderance of the evidence.
• Forensic scientists can testify on either side.
• Forensic scientist's day in court happens with an analysis, is used to make the report and used to issue a Subpoena.
• Other requirements are Voir Dire to test the Background, training, and experience, Direct Examination must Lay foundation for the admissibility of the evidence question, and after that a Cross Examination can either discredit the witness or evidence and then Re-direct and Re-cross.

Ethics and Forensic Science

• There are no specific code of ethics, but there are ethics inside The American Academy of Forensic Sciences.
• The general rule is to do the best work, on every case that is submitted, providing a complete and honest report of findings, and testify with their scientific opinion based on the report and their knowledge in the field.
• Any difference of opinion between experts from the the same evidence are always ethical.
• Presents and defends; the trier of fact makes the ultimate decision.
• If you work in a police DNA lab, you would not have to have supportive results in their report, as you have to report all results as they are.