#2 - History

The Development of Forensic Science

Forensic science has evolved significantly over the years, heavily influenced by early pioneers who laid the groundwork for modern techniques. This transformation has been crucial in the advancement of justice and the scientific evaluation of evidence in criminal cases.

Sir Arthur Conan Doyle

• Sir Arthur Conan Doyle was instrumental in popularizing scientific crime detection through his fictional character Sherlock Holmes, who showcased methods that were groundbreaking for his time.

• Holmes utilized techniques such as forensic science and deductive reasoning, which predated actual implementation of these methods in police work.

Impact of Sherlock Holmes

• In 1887, Doyle published A Study in Scarlet, where Holmes highlights the importance of scientific methods in solving crimes.

• He famously declares the discovery of a reagent that tests for hemoglobin, emphasizing more reliable blood stain tests over previous methods like the guaiacum test, a technique known for its false-positive results.

• The narrative illustrates the capability of scientific approaches to prevent wrongful acquittals and enhance the accuracy of criminal investigations.

Historical Perspective Timeline – Pioneers in Forensics

1. Mathieu Orfila (1787 – 1853): Known as the Father of Forensic Toxicology, his work laid the foundations for the field.

   • Authored a seminal treatise focused on the detection of poisons and their effects on both humans and animals in 1814.

   • Notable forensic case: The poisoning trial of Marie LaFarge (1840) involved his use of innovative techniques to prove that arsenic was present, showcasing the critical need for rigorous scientific investigation.

2. Alphonse Bertillon (1853 – 1914): Referred to as the Father of Criminal Detection, he pioneered anthropometry, the use of body measurements for personal identification in 1879.

   • His methods were eventually surpassed by fingerprinting, but his contributions were vital in the early days of criminal identification.

3. Francis Galton (1822 – 1911): Conducted comprehensive research on fingerprints, publishing Finger Prints in 1892, which established systematic classification systems still in use today.

4. Leone Lattes (1887 – 1954): Developed groundbreaking methods for identifying blood types (A, B, AB, O) from dried bloodstains, revolutionizing forensic blood analysis and enabling accurate investigations.

5. Calvin Goddard (1891 – 1955): Instrumental in the field of forensic ballistics; he introduced and refined the use of comparison microscopes for analyzing bullets to determine whether a specific firearm had discharged a particular bullet. His work advanced the field significantly and is still foundational in forensic lab practices.

6. Albert S. Osborn (1858 – 1946): Authored Questioned Documents in 1910, establishing document examination principles that paved the way for the acceptance of documents as scientific evidence in courts of law.

7. Edmond Locard (1877 – 1966): Developed the critical crime lab principle known as Locard's Exchange Principle, which states that whenever two surfaces come in contact, material is exchanged. This principle serves as a foundational theory in all crime labs and forensic investigations, emphasizing the importance of trace evidence.

Organization of a Crime Laboratory

Since the 1960s, the demand for scientific evaluation of evidence has led to the establishment of over 350 crime labs in the U.S.

• There is an increasing emphasis on addressing drug-related crimes and the application of DNA profiling in solving cases.

Basic Services of Crime Labs

• Standard Units:

  • Physical Science: Applies principles of chemistry and physics to analyze crime scene evidence.

  • Biology: Provides analysis of biological fluids, hair, fibers, and conducts DNA testing to identify suspects or victims.

  • Firearms and Ballistics: Focuses on examining firearms, ammunition, and associated ballistic evidence to ascertain gun-related crime details.

  • Document Examination: Involves the analysis of questioned documents, handwriting evaluations, and printing comparisons to confirm authenticity.

  • Photography: Utilizes advanced techniques such as digital, infrared, and ultraviolet photography to capture evidence in multiple spectrums.

• Specialized Forensic Units:

  • Toxicology Unit: Responsible for analyzing body fluids to detect the presence of drugs, poisons, and toxins.

  • Latent Fingerprint Unit: Dedicated to processing crime scenes for the recovery and analysis of invisible fingerprints.

  • Polygraph Unit: Employs lie detection techniques as a supplementary tool in investigations.

Forensic Analysis Techniques

• Organic Analysis: This encompasses sophisticated techniques like chromatography and mass spectrometry which are essential for separating and identifying compounds in samples.

• Inorganic Analysis: Techniques include atomic absorption spectroscopy and X-ray diffraction, used for analyzing the elemental composition of materials.

Forensic Pathology

Forensic pathologists play a critical role in determining the cause of death through detailed autopsies.

• Death Classification: Deaths are categorized into natural, homicide, suicide, accident, and undetermined, each requiring specific investigation protocols.

• Key Post-Mortem Changes: Rigor mortis, livor mortis, and algor mortis are critical changes that forensic pathologists assess to establish time and circumstances of death.

Forensic Anthropology

This branch focuses on the examination of skeletal remains to establish identity and deduce characteristics like ethnicity, sex, and age, which can provide crucial context in legal investigations.

Forensic Entomology

Utilizing knowledge of insect life cycles, forensic entomologists can estimate the time of death based on the types of insects present and their developmental stages at a crime scene.

Forensic Psychiatry

This specialty involves analyzing behavioral disorders and assessing the competency of individuals for legal cases, particularly those involving criminal behavior.

Forensic Odontology

Forensic odontologists compare bite marks found at crime scenes with dental records or suspect teeth to assist in the identification process. This can be pivotal in cases of physical assault and homicide.

Forensic Engineering

Forensic engineers investigate accidents and failures in structures or machinery, determining potential causes related to human error, design flaws, or explosive incidents. This is essential for improving safety and accountability.