Introduction to Forensic Science

Course Structure and Syllabus Specifications

Course Details:
- Course Code & Name: GSCI 115: Intro to Forensic Science.
- Institution: Holy Family University.
- Instructor: Geoff Toner, MS, MBA.
Required Text Information:
- Title: Criminalistics: An Introduction to Forensic Science (13th Edition).
- Authors: Richard Saferstein and Tiffany Roy.
- Textbook Utilization: Assigned readings, homework assignments (Review Questions, Application & Critical Thinking exercises), test questions, and case files.
Grading Scheme and Deliverables:
- Tests: $2$ exams at $100\text{ points}$ each ( $20\%$ of final grade).
- Quizzes: $6$ quizzes at $50\text{ points}$ each ( $30\%$ of final grade).
- Assignments: Lecture and laboratory assignments at $25\text{ points}$ each ( $40\%$ of final grade).
- Final Exam: $1$ cumulative final examination at $100\text{ points}$ ( $10\%$ of final grade).

Fundamentals and Definition of Forensic Science

Broad Definition:
- Forensic Science is defined broadly as the application of science to criminal and civil laws.
- Here the emphasis is on those laws enforced by police agencies in a criminal justice system.

Pioneers and Historical Evolution of Forensic Science

Mathieu Orfila:
- Recognized as the "Father of Forensic Toxicology".
- Developed principles and techniques needed to compare physical evidence regarding poisons and toxic substances.
Alphonse Bertillon:
- Devised the first scientific system of personal identification in $1879$ .
- Introduced Bertillonage (anthropometry), which utilized a series of precise body measurements to identify individuals.

Alphonse Bertillon system of personal identification showing anthropometric measurement steps

Francis Galton:
- Conducted the first definitive study of fingerprints and devised a system for their classification.
- Established categories for fingerprint patterns, including Arch (A), Loop (L), and Whorl (W).

Fingerprint classification patterns showing Arch, Loop, and Whorl

Leone Lattes:
- Developed a procedure to determine blood type from dried bloodstains.

ABO Blood Group chart showing red blood cell antigens and plasma antibodies

Calvin Goddard:
- Refined firearms identification (ballistics) to determine if a particular gun fired a specific bullet.
- Introduced the comparison microscope as an essential tool for firearms analysis.
Albert Osborn:
- Developed the fundamental principles of document examination and handwriting analysis.

Handwriting comparison showing structural differences, connecting strokes, slant, and baseline alignment

Walter McCrone:
- Advanced the field of microscopy and its application to examining physical evidence.
Hans Gross:
- Authored the first study describing the application of scientific principles to the field of criminal investigation.
Edmond Locard:
- Incorporated Hans Gross's principles within a working crime laboratory.
- Locard's Exchange Principle: States that when a person comes in contact with an object or another person, a cross-transfer of materials occurs.

Locard Exchange Principle triangle linking crime scene, victim, suspect, and physical evidence

Organization and Expansion of Crime Laboratories

Current Scale and Facility Scope:
- Approximately $411$ public crime laboratories operate across federal, state, county, and municipal levels.
- A primary federal facility is the Federal Bureau of Investigation (FBI) laboratory in Quantico, VA.

FBI Laboratory facility building in Quantico, VA

Key Causes of Crime Laboratory Expansion:
- Supreme Court Decisions: Judicial rulings mandating that police place greater emphasis on securing scientifically evaluated evidence.
- Drug Evidence Volume: An ever-increasing number of drug specimens requiring chemical analysis.
- DNA Profiling: The advent and widespread application of DNA profiling.

Functional Units of Full-Service Crime Laboratories

Five Basic Technical Services:
- Physical Evidence Unit:
- Incorporates principles of chemistry, physics, and geology to identify and compare physical evidence.
- Analyzes evidence such as drugs, glass, paint, explosives, and soil.
- Biology Unit:
- Applies knowledge of biological sciences to investigate biological fluids or touch samples for DNA.
- Performs comparative analyses on hair and fiber samples.

Forensic scientist analyzing DNA banding pattern gel on a lightbox

Firearms Unit:
- Investigates discharged bullets, cartridge cases, shotgun shells, and ammunition.
- Conducts tool mark comparisons to link tool impressions to specific implements.

Firearms examiner inspecting a rifle receiver action

Document Examination Unit:
- Provides skills required for handwriting analysis.
- Analyzes questioned document issues, including obliterations, erasures, burnt documents, paper composition, ink, photocopier toner, and typescript comparison.

Forensic questioned document examination features on an evidence envelope

Photography Unit:
- Applies specialized photographic techniques for recording and examining physical evidence.
- Uses techniques including digital, infrared, ultraviolet, and X-ray photography.

Forensic photographer taking photographs of evidence with a camera setup

Additional/Optional Full-Service Units:
- Toxicology Unit: Examines body fluids and organs to determine the presence or absence of drugs and poisons.
- Latent Fingerprint Unit: Processes and examines evidence for latent (hidden) fingerprints.
- Polygraph Unit: Conducts polygraph (lie detector) examinations.
- Voiceprint Analysis Unit: Uses sound spectrographs to analyze voice recordings and transform speech into visual graphic displays (voiceprints) for speaker identification.

Voiceprint analysis plots showing time domain, frequency domain, and spectrogram representations of speech

Crime Scene Investigation Unit: Dispatches specially trained personnel to crime scenes to collect and preserve physical evidence.

Role and Methodology of the Forensic Scientist

Analysis of Physical Evidence:
- Skilled in applying the principles and techniques of physical and natural sciences to analyze evidence recovered during criminal investigations.
- Analytical techniques must be validated using the scientific method: $\text{Observation} \rightarrow \text{Question} \rightarrow \text{Hypothesis} \rightarrow \text{Experiment} \rightarrow \text{Analysis} \rightarrow \text{Conclusion}$

Flowchart showing the steps of the Scientific Method from observation to conclusion

Expert Testimony:
- Expert Witness: An individual whom the court determines possesses knowledge relevant to the trial that is not expected of the average person.
- Role: Evaluates evidence based on specialized training and experience that the court lacks, expressing an opinion regarding the significance of the scientific findings.

Forensic expert presenting evidence testimony in a court of law

Legal Standards Governing Evidence Admissibility

The Frye Standard (Frye v. United States):
- Set legal guidelines for determining admissibility of scientific evidence in the courtroom.
- Requires that the scientific procedure or technique be "generally accepted" by a meaningful segment of the relevant scientific community.
The Daubert Standard (Daubert v. Merrell Dow Pharmaceuticals, Inc., 1993):
- Asserted that the Frye standard of "general acceptance" is not an absolute prerequisite to the admissibility of scientific evidence.
- Established that trial judges are ultimately responsible as "gatekeepers" for the admissibility and reliability of scientific evidence and expert testimony.
- Five Daubert Guidelines/Criteria:
1. Whether the scientific technique or theory can be (and has been) tested.
2. Whether the technique or theory has been subject to peer review and publication.
3. The technique's known or potential rate of error.
4. Existence and maintenance of operational standards controlling the technique's operation.
5. Whether the scientific theory or method has attracted widespread acceptance within a relevant scientific community.
Other Landmark Admissibility Decisions:
- Kumho Tire Co., Ltd. v. Carmichael (1999): Determined that the judge acts as a "gatekeeper" not only for scientific testimony, but for any expert testimony.
- Melendez-Diaz v. Massachusetts (2009): Determined that an expert witness must appear in person to provide testimony in court so that the defense has an opportunity to cross-examine the witness.

Crime Scene Evidence Collection Procedures

Evidence Technicians:
- Personnel trained directly by crime lab staff who are on $24\text{-hour}$ call for evidence collection at crime scenes.
- Training ensures all pertinent evidence is recognized, preserved, and collected properly.
Alternative Training Methods:
- Where no formal evidence technicians exist, law enforcement officers gain familiarity through lectures, tours of the crime laboratory, and evidence collection manuals.

Crime scene investigator photographing a victim and evidence markers at a death investigation scene

Specialized Disciplines in Forensic Science

Forensic Psychiatry:
- Examines the relationship between human behavior and legal proceedings (e.g., competency trials, criminal sanity evaluation, behavioral profiling).
Forensic Odontology:
- Uses dental remains and X-rays to establish the identity of victims when left in an unrecognizable state.
- Investigates bite marks (noted as a controversial forensic discipline).

Dental X-rays illustrating dental restorations used for individual identification

Forensic Engineering:
- Concerned with failure analysis, accident reconstruction, structural collapses, and determining the origins or causes of fires or explosions.

Cell tower disguised as a tree illustrating technological infrastructure investigation

Forensic Computer and Digital Analysis:
- Involves the identification, collection, preservation, and examination of digital evidence from computers, cell phones, and electronic media.

Digital evidence collection from a mobile smartphone