Criminalistics and Forensic Science: Comprehensive Study Guide

Definition and Scope of Forensic Science

Broad Definition: Forensic science is the application of science to criminal and civil laws.
Criminalistics: This is a specific term often used interchangeably with forensic science to describe the application of science to laws enforced by police agencies in a criminal justice system.
Primary Disciplines Involved: Forensic science integrates various professional disciplines into the legal realm, specifically: * Chemistry * Biology * Physics * Geology

The Relationship Between Science and Law

Regulatory Agencies: Science is applied to civil laws through agencies that regulate: * The environment * Food and drugs * Auto emissions * The burning of fuels * Water purity * Pesticide use and regulation
Scientific Support for Law Enforcement: As crime rates increase, laws are often revived or updated. Public concern regarding the presence of law enforcement increases proportionally. Science provides essential advice and technical support to these efforts.
Limitations: Science provides technical data but does not address social or psychological issues surrounding crime.

The "CSI Effect": Perception vs. Reality

Essential Question: Do television shows like CSI have a negative influence on the interpretation of the criminal justice system? The conclusion is yes; viewers often fail to distinguish between television fiction and reality.
Nolo’s Plain-English Law Dictionary Definition: The "CSI Effect" is a phenomenon reported by prosecutors where jurors, influenced by scientific crime-solving shows, are reluctant to convict when forensic evidence is neither necessary nor available.
Causes: Popular shows like CSI, NCIS, and Law and Order employ exaggerated methods of evidence investigation to maintain viewer engagement.
Impact on Legal Proceedings: * Jurors demand more evidence in criminal trials. * The standard of proof is effectively raised for prosecutors. * Jurors place a lower value on circumstantial evidence and demand physical proof that may not exist.
Increased Interest: While the "CSI Effect" creates hurdles in court, it has led to a significant increase in the number of students interested in studying forensic science.
CSI vs. Real Life: Operational Differences: * Fingerprints: In CSI, fingerprints are found everywhere in "evidential value" condition. In real life, fingerprints are difficult to find at a crime scene. * DNA Processing: In CSI, DNA takes minutes to process. In real life, it can take weeks. * Legal Procedures: In CSI, investigators often bypass warrants. In real life, investigators must obtain a warrant before making an arrest or searching a scene. * Atmosphere and Workload: Television depicts chaotic scenes with no paperwork where one person performs many jobs. Reality involves controlled environments, extensive paperwork to ensure court admissibility, and jobs divided among multiple specialists. * Terminology: Television characters use the term "match" to describe a definitive relationship. Forensic technicians use less definite terms to acknowledge that absolute certainty is often impossible.
Public Attitude Study Results: * Perceived Reliability of Evidence: * DNA: $89.5\%$ (Considered most reliable) * Fingerprints: $78.8\%$ * Medical Expert Testimony: $30.3\%$ * Police Testimony: $23.3\%$ * Victim Testimony: $21.2\%$ * Eyewitness Testimony: $21.2\%$ * Science-Based vs. Human-Based Testimony: Respondents found all "science-based" evidence (DNA/fingerprints) significantly more reliable than human-based testimony. * Viewing Habits: Individuals who watched $3$ or more hours of crime shows per week were less likely to convict in rape or murder cases without scientific evidence. Willingness to convict is directly affected by the volume of crime programs watched.

History and Origins of Forensic Science

Ancient Evidence: * Prehistoric: Fingerprint evidence found in early paintings and rock carvings. * $700$ AD: The Chinese used fingerprints to establish identity on clay sculptures and documents, though no formal classification system existed. * $1248$ : The Chinese recorded the first application of medical knowledge to crime solving by describing how to distinguish drowning from strangulation.
Etymology: The word "forensic" originates from the Latin forum, meaning "a marketplace." In Roman times, criminal charges were presented in public speeches; the best argumentation determined the outcome.

Historical Timeline of Forensic Science Development

$1686$ : First notes recorded regarding fingerprint characteristics.
$1784$ : John Toms (England) was convicted of murder by matching a piece of newspaper in his pocket to a wad found at the crime scene.
$1836$ : James Marsh (Scottish chemist) was the first to use toxicology (arson detection) in a jury trial.
$1864$ : Odelbrecht advocated using photographs for criminal identification and documenting crime scenes.
$1880$ : First recorded use of fingerprints to solve a crime in Tokyo.
$1887$ : First Sherlock Holmes novel published.
$1891$ : Hans Gross coined the term "criminalistics."
$1901$ : Development of techniques for blood type detection.
$1903$ : The New York State prison system began using fingerprints for criminal identification.
$1905$ : Establishment of the Federal Bureau of Investigation (FBI).
$1910$ : First police crime laboratory established in France.
$1920$ : Edmond Locard developed the "Exchange Principle."
$1923$ : August Vollmer established the first U.S. crime lab in Los Angeles.
$1924$ : John Larson invented the modern polygraph unit.
$1932$ : FBI crime lab established under J. Edgar Hoover.
$1941$ : Beginning of voiceprint identification.
$1945$ : Test for semen presence developed.
$1948$ : Vollmer established the Criminology & Criminalistics Department at UCAL-Berkeley.
$1954$ : Breathalyzer for field sobriety testing invented.
$1977$ : AFIS (Automated Fingerprint Identification System) introduced by the FBI.
$1986$ : First use of DNA to solve a crime.
$1991$ : IBIS (Integrated Ballistics Identification System) launched for comparing bullets and cartridge cases.
$1996$ : FBI introduced computerized searches of the AFIS database.

Sir Arthur Conan Doyle and Sherlock Holmes

Contribution: Popularized physical detection methods in crime scenes through the character of Sherlock Holmes.
A Study in Scarlet ( $1887$ ): Within this novel, Doyle describes a scientific test for bloodstains (the "Sherlock Holmes's test") that reacts with hemoglobin.
Verbatim Quote: "I have found a re-agent which is precipitated by haemoglobin, and by nothing else… The old guaiacum test was very clumsy and uncertain… Now, this appears to act as well whether the blood is old or new."

Key Pioneers in Forensic Science

Mathieu Orfila: Known as the "father of forensic toxicology." He published a treatise on poison detection and its effects on animals.
Alphonse Bertillon: Devised the first scientific system of personal identification in $1879$ . This system relied on a series of bodily measurements to identify individuals.
Francis Galton: Conducted the first definitive study of fingerprints and their classification; published Finger Prints in $1892$ .
Leone Lattes: Developed a specific procedure to determine blood type from dried bloodstains.
Calvin Goddard: A U.S. Army Colonel who utilized the comparison microscope to determine if a specific gun fired a bullet.
Albert Osborn: Developed the fundamental principles of document examination; published Questioned Documents in $1910$ .
Walter McCrone: Utilized microscopy and analytical methodologies to examine evidence.
Hans Gross: A judge and prosecutor who wrote the first treatise describing the application of scientific principles to criminal investigation.
Edmond Locard: Incorporated Gross’s principles into a workable crime laboratory. He is famous for Locard’s Exchange Principle, which states: "When a criminal comes in contact with an object or person, a cross-transfer of evidence occurs."

Development and Organization of Crime Laboratories

FBI Laboratory: Organized by J. Edgar Hoover in $1932$ . It is currently the world's largest forensic lab, performing over $1,000,000$ analyses per year. In $1981$ , the Forensic Science Research and Training Center was established in Quantico, VA.
Growth in the United States: Development has been rapid but characterized by a lack of national and regional coordination. There are approximately $411$ public crime labs at the federal, state, county, and municipal levels.
Factors for Growth: * Supreme Court decisions in the $1960s$ forced police to place greater emphasis on scientific evidence. * The drug abuse crisis caused labs to be inundated with drug specimens. * The advent of DNA profiling.
Great Britain System: National system of regional labs overseen by the "Home Office" using a "Fee for Service" concept for police and defense attorneys.

New Jersey State Crime Laboratory System

History: * $1920$ : Newark City Police setup a lab. * $1936$ : NJ State Police setup a lab in West Trenton.
Current Infrastructure (Office of Forensic Science): * Central Laboratory: Hamilton ( $2004$ ) * North Regional Lab: Little Falls ( $1972$ ) * South Regional Lab: Hammonton ( $1973$ ) * East Regional Lab: Sea Girt ( $1980$ )
NJ State Police Services: Drugs and Toxicology, Criminalistics (including Biology Unit), DNA Analysis, and Ballistics Unit (Hamilton).

Technical Support and Services of the Crime Laboratory

Five Basic Services:

Physical Science Unit: Uses chemistry, physics, and geology to identify and compare physical evidence.
Biology Unit: Investigates blood samples, body fluids, hair, and fiber samples.
Firearms Unit: Examines discharged bullets, cartridge cases, shotgun shells, and ammunition.
Document Unit: Handles handwriting analysis and questioned-document issues.
Photographic Unit: Records and examines physical evidence using specialized techniques.

Optional Services:

Toxicology Unit: Checks body fluids/organs for drugs and poisons.
Latent Fingerprint Unit: Processes/examines latent fingerprint evidence.
Polygraph Unit: Conducts lie detector tests.
Voiceprint Analysis Unit: Attempts to link recorded voices to suspects.
Evidence-Collection Unit: Dispatches trained personnel to collect and preserve physical evidence at crime scenes.

Application of the Scientific Method in Forensic Science

The Scientific Method Process: 1. Formulate a question worthy of investigation. 2. Formulate a reasonable hypothesis to answer the question. 3. Test the hypothesis through experimentation. 4. Validation: Upon validation, the hypothesis becomes suitable as scientific evidence.
Everyday Example (Allergy): * Observation: You visit a friend with a new cat and begin sneezing. * Hypothesis: You are allergic to cats. * Experiment 1: Leave the house. If sneezing stops, the hypothesis is supported. * Experiment 2: Visit a different friend with a cat. If sneezing recurs, the hypothesis is further supported. * Theory: Results indicate you are indeed allergic to cats.

Skills of a Forensic Scientist and Legal Admissibility

Professional Skillset: A scientist must apply physical and natural science principles to analyze evidence recovered during investigations.
Expert Witness: An individual determined by the court to possess knowledge relevant to the trial that the average person lacks. They express an opinion on the significance of findings.
Melendez-Diaz v. Massachusetts: Imposed the necessity for forensic scientists to appear in court.
Legal Standards for Admissibility: * The Frye Standard (Frye v. United States): Evidence must be "generally accepted" by the scientific community to be admissible. * The Daubert Standard (Daubert v. Merrell Dow Pharmaceutical, Inc. $1993$ ): The Supreme Court ruled that the Frye standard is not an absolute prerequisite. Trial judges act as "gatekeepers." * Daubert Criteria for Adjudication: 1. Whether the technique or theory can be (and has been) tested. 2. Whether it has been subject to peer review and publication. 3. The potential rate of error. 4. The existence and maintenance of standards controlling the technique. 5. Widespread acceptance within a relevant scientific community.

Specialized Forensic Services

Forensic Psychiatry: Examines the relationship between human behavior and legal proceedings.
Forensic Odontology: Uses teeth for identification in unrecognizable bodies and investigates bite marks.
Forensic Engineering: Focuses on failure analysis, accident reconstruction, and causes/origins of fires or explosions.
Forensic Computer Science: Examination of digital evidence.
Forensic Anthropology: Identification and examination of human skeletal remains.
Forensic Entomology: Study of insects in relation to criminal investigations.