Chapter 1: Introduction to Forensic Science Forensic science – the application of scientific knowledge and technology to crime-solving. As scientific technologies increase, law enforcement agencies look more and more to the scientific community for advice and support Science’s role is to supply accurate & objective information reflecting events that have occurred at a crime
History and Development of Forensic Science: Sir Arthur Conan Doyle popularized scientific crime-detection methods through his fictional character Sherlock Holmes Sherlock Holmes applied the newly developing principles of serology (topics relating to blood), fingerprinting, firearm ID, and document examination long before they were used for real investigations.
**Insert slides about historical figures**
Services of a Crime Lab Basic Services: 1. Physical Science Unit – uses chemical tests and analytical instruments to exam drugs, glass, paint, explosives, soil.
2. Biology Unit – blood stain and other body fluids analysis, hair and fibers analysis, plant identification
3. Firearms Unit – ballistics, firearm discharge residue 4. Document Examination Unit – checking authenticity
5. Photography Unit – may use specialized photography, such as infrared or X-ray.
Optional Services 1. Toxicology Unit – analyze biological specimens for drugs, poisons
2. Latent Fingerprint Unit – analyze fingerprints left on a surface 3. Polygraph Unit – lie detection
4. Voiceprint Analysis Unit – analyzes recordings for an individual’s unique sound patterns
5. Evidence Collection Unit – they collect and preserve physical evidence found at a crime scene
Specialized Forensic Science Services (outside the crime laboratory) 1. Forensic Pathology – the investigation of sudden, unnatural, unexplained or violent deaths. Medical examiners perform autopsies to establish the cause of death – 5 categories: - natural, homicide, suicide, accident, or undetermined
Time of death is established by looking at: - rigor mortis - stiffening that starts within 24 hours after death and disappears within 36 hours - livor mortis – the settling of blood in areas of the body closest to the ground – begins immediately after death and lasts for up to 12 hours - algor mortis – the process of body temp. continually cooling after death. The rate is about 1 to 1.5°F per hour
2. Forensic Anthropology – the identification and examination of human skeletal remains
3. Forensic Entomology – the study of insects and their relation to a criminal investigation - insects such a blow flies are the first to infest a dead body - the stage of development of the fly larvae can approximate the time of death
4. Forensic Psychiatry – the relationship between human behavior and legal proceedings For ex., determining whether people are competent to stand trial
5. Forensic Odontology – examination of teeth - can identify a person - bite mark analysis
6. Forensic Engineering – accident reconstruction, failure analysis, fires, and explosions