The Crime Scene: How Forensic Science Works
Written By W. Mark Dale, MBA and Wendy S. Becker, Ph.D
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257 pages; Paperback
INTRODUCTION
Carl Selavka, a very experienced Ph. D. forensic toxicologist and forensic laboratory manager, provides an enticing analyses of forensic science today and looks to the future. Dr. Selavka’s thoughts on forensic science and science in general provide excellent insights for any layman, forensic scientist or aspiring forensic student considering a forensic science career.
Chapter 1: Crime Scene Scenario
The authors create a fiction homicide scene that brings to life the daily tasks of forensic professionals. A fictional homicide investigation and sidebars from the author’s “real world” of forensic science are strategically placed within the text to provide a linkage to applications of forensic science to a criminal investigation. The Laura Lake homicide’s fictional characters demonstrate the forensic team’s roles and interactions essential for solving crimes. Principles of comparison and new technologies are explained and introduced to the reader.
- Every Contact Leaves Its Trace – The Locard Principle
- The Concept of Known and Questioned Evidence
- Combined DNA Index System , CODIS
- National Integrated Ballistic Information Network , NIBIN
- Automated Fingerprint Identification System, AFIS
Chapter 2: First Responder
The First Responder is arguably the first and most important step of the forensic process, Evidence must be recognized, collected, protected from loss – contamination – degradation, and documented for court. There is only one chance to process the scene and properly collect evidence.
- The RESPOND Protocol
- Respond
- Evaluate
- Secure
- Protect
- Observe
- Notify
- Document
Chapter 3: Team Responsibilities at the Crime Scene
Law enforcement officers, crime scene technicians, emergency personnel, forensic scientists, pathologists and prosecutors work as a team to investigate a crime and analyze evidence. Steps in the forensic process must be done properly in a sequential order.
- Crime Scene Leader
- Photographer
- Sketch Preparer
- Evidence Custodian
- Chain of Custody
- Evidence Recovery
- Bagging and Tagging
Chapter 4: Collection, Preservation and Documentation of Evidence
All tasks performed during the processing of a crime scene must be documented accurately at the time the task was performed using notes, standardized documents and photography.
- Preparation
- Approaching the Scene
- Securing and Protecting the Scene
- Initiating a Preliminary Survey – The Initial Walk Through
- Evaluating Physical Evidence Possibilities
- Preparing Narrative Description
- Depicting Scene Photographically
- Preparing a Diagram or Sketch of the Scene
- Conducting a Detailed Search and Collecting Physical Evidence
- Chain of Custody, Evidence Sealing and Storage
- Transfer of Evidence
- Conducting Final Survey and Releasing the Crime Scene
Chapter 5: Recording the Crime Scene
A crime scene personnel use sketches, diagrams and photography to record a crime scene and prepare for court presentations.
- Photography
- Crime Scene Sketch
- Crime Scene Search
- Methods of Search
- Outside
- Strip Method
- Grid Method
- Circle Method
- Zone Method
- Indoors
- Searching a Vehicle
Chapter 6: Collection of Latent Fingerprints and Blood
Latent fingerprints and now human fluids are the most important means of placing an individual at the scene or in contact with a probative item or surface.
- Latent Prints
- Developing Latent Prints
- Blood Stains and Blood Spatter Patterns
- Protection From Blood-Born Pathogens
- BIOTRACKS Program
- Blockade Analysis Solves Crime
- Example of a Method for Latent Print Development
Chapter 7: Collection and Protection of Questioned Documents, Fibers and Firearms
Questioned Documents compare handwriting, writing substrates and writing tools. Natural and synthetic fibers are often used to connect an individual to a crime scene or vehicle. Firearms, projectiles and cartridges are examined to compare weapons to bullets and casings found at the scene or autopsy.
- Questioned Documents
- Fibers
- Firearms and Ammunition
Chapter 8: Collection of Impressions, Hair and Toxicology
Impressions from footwear, tools or most any object are compared to known exemplars. Hair is categorized by major differentiating characteristics of race and then screened for biological materials slated for DNA analyses. Microscopic hair comparisons are becoming less probative. Toxicology detects and quantifies minute traces of prescription drugs, controlled substances and noxious materials that cause physical / mental impairment and death.
- Footwear and Tires
- Hair
- Tool Marks
- Toxicology Specimens
Chapter 9: Collection of Evidence from the Autopsy
Jackie Higgins, our author for this chapter, is an experienced forensic molecular biologist and assisted in hundreds of autopsies at the beginning of her forensic career. Jackie provides a very detailed description of the autopsy process and introduces the reader to many medical terms used to describe the cause and manner of death. The autopsy is designed to explain the cause and manner of death. The autopsy is also a crime scene. Evidence is recognized, collected and protected using the same processes employed at the crime scene.
- Coroner’s System versus Medical Examiner’s System
- The Death Certificate: Cause and Manner of Death
- Information Assessed at the Autopsy
- Dissection of the Forensic Autopsy
- Blunt Force Trauma
- Toxicology
- Cause of Death
Chapter 10: Processing a Vehicle
In most circumstances, a vehicle is used for travel to and from the crime scene. An alert officer safe guards a vehicle for proper forensic processing and evidence collection.
- A One-Car Property Damage Accident
- Personal Injury in Single or Multi-Vehicle Accidents
- Vehicular Homicide Multi-Vehicle or Pedestrian Accident
- Vehicle Used in the Commission of a Crime
- Driver or Passenger Impaired With Alcohol, Prescribed Drugs,
- Illegally Possessed Controlled Substances
- Vehicle Interior
- Vehicle Exterior
Chapter 11: The Laboratory Analyses
The forensic laboratory develops data for the criminal investigators. Often, laboratory analyses, data and opinions can include or exclude suspects early in the investigation, providing cost benefit and increased efficiency. The investigator must be aware of all forensic disciplines that can develop facts and scientific opinions for the investigation.
- Evidence Receiving
- Drug Section
- Analysis of Drug Samples
- Categories of Analytical Techniques
- Samplingn Scheme – A Decision Flowchart
Chapter 12: Biology
Biology has progressed from ABO typing, to Electrophoresis, Restriction Length Polymorphisms and now Single Tandem Repeats. Detection limits have decreased to leverage “invisible contact” evidence.
- Four Ways to Obtain DNA
- Blood
- Presumptive Test with Samples That Contain Blood and Ascorbic Acid
- Seminal Fluid and Sperm
- Methods Used To Collect and Screen for presence of Seminal Fluid and Semen
- Sexual Assault Evidence Kits
- DNA
Chapter 13: Firearms and Tool Marks
Firearms remain a challenge for law enforcement and community safety. New imaging and computer technologies enable the laboratory to make more comparisons in a timely manner.
- Firearms
- Safety
- Firearms Job Responsibilities and Tasks
- New York State Penal Code Section 265
- New technology (NIBIN)
- Tool Marks
Chapter 14: Toxicology, Hair and Fibers
Toxicology analyses can detect nanogram amounts of controlled substances, prescription drugs or other noxious materials in human physiological fluids or tissues. These substances can cause impairment or death.
Hairs and fibers are commonly called the “trace” items of evidence and are examined microscopically with a variety of optical equipment and alternate light sources.
- Toxicology
- How a Persistent Toxicologist Solves A Case
- Hair. Vacuum Cleaner Analysis and Wayne Williams Case
- Fibers
Chapter 15: The Case Triage Team and Hypothesis Development
What type of scientific reasoning is used to solve a case. How are different theories identified, examined, included or excluded. This is where all the evidence, analyses and opinions solve the crime.
- The Lead Desk Concept
- The Scientific Method
- Hypothesis Testing, Inductive and Deductive Reasoning
- Preconceived Bias, Perception and Inference
- Gathering and Interpreting Data With The Case Triage Team
- Evidence Analyses Progress Chart
Chapter 16: Legal Issues
Robert Conflitti, past prosecutor and trainer at the New York Prosecutor’s Training Institute, the author of this chapter provides a professional and beginning student overview we all can find helpful in preparation for our testimony. The main difference between science and forensic science is forensic science is presented in courts of law. The forensic scientist must provide clear and concise testimony with no bias.
- Legal Issues in the Gathering of Forensic Evidence
- Search Incident to Arrest
- Consent
- Automobiles
- Inventory
- Exigent Circumstances
- Plain View
- Court Room Presentation
- Documentation
- Preparation
- Testimony
- Qualifications
- Conversational Language
- Inaccurate Language
- Using Analogies
- Eye Contact
- Direct and Cross-Examination
- Refreshing Recollection
- Daubert vs. Dow Pharmaceuticals
- Visual Aids
- Cross-Examination With Literature
- Calculations
Chapter 17: New Forensic Technology
Computers have revolutionized forensic science. Comparisons between Questioned and Known items is now done in minutes, as compared to specific individual comparison requests that used to take weeks or months.
- Integrated Automated Fingerprint Identification System (IAFIS)
- Law Enforcement Online (LEO)
- National Instant Criminal Background Check System
- National Crime Information Center (NCIC)
- Uniform Crime Reporting/National Incident Based-Reporting (UCRNIBR)
- National Integrated Ballistic Imaging Network (NIBIN)
- Combined DNA Index System (CODIS)
- CODIS Structure
- DNA Database Performance Metrics & CODIS Funding
- Computer Crime and Digital Evidence
Chapter 18: Police and Laboratory Culture
Is the police organizational culture a fit for you? The reader will examine the culture of most forensic laboratories within police departments. Forensic students and future forensic scientists must examine the defining characteristics of their future employment environment.
Chapter 19 Becoming a Forensic Professional
How does a high school graduate or a college student decide the best path to pursue a career in forensic science. Dr. Donald Orokos, University at Albany – Director of Graduate Program in Forensic Molecular Biology, selects only the best students for his forensic program. As author of this chapter, he provides the inside view on how to be a successful forensic student and future forensic scientist.
Appendix A: Selected References
Appendix B: Colleges and Universities
Appendix C: More Resources on the Forensic Sciences
Appendix D: Forensic Science Technician Job Analysis
Appendix E: ISO references
Appendix F: Author’s Forensic Management Research