Introduction to Forensic Science (Module 1)
- 2. Introduction to Forensic Science: Learning Objectives • Define forensic science • Explain the development of forensic science throughout history • Describe the services of a typical comprehensive crime laboratory in the criminal justice system • Explain the role and responsibilities of the expert witness
- 3. Introduction to Forensic Science: Vocabulary • Expert Witness • Locard’s Exchange Principle • Scientific Method
- 4. CASEY ANTHONY: THE CSI EFFECT? • July 15, 2008 • Cindy Anthony makes a 911 call reporting that her granddaughter Caylee is missing – Caylee has not been seen in 31 days – When she asked her daughter, Casey, gives a variation of explanations as to Caylee’s whereabouts – Finally, Casey confesses to Cindy she has not seen Caylee in weeks
- 5. CASEY ANTHONY: THE CSI EFFECT? • State and nation-wide search for Caylee Anthony begins as Casey tells authorities that Caylee was kidnapped by a nanny on June 9 • December 11, 2008 • Caylee’s remains are found in a blanket inside of a trash bag in a wooded area near the family home
- 6. CASEY ANTHONY: THE CSI EFFECT? • The state’s theory was that Casey used chloroform to render Caylee unconscious • Placed duct tape over Caylee’s mouth and nose • Kept her remains in the trunk of her car for several days before disposing it • Casey is charged with first-degree murder in October 2008
- 7. CASEY ANTHONY: THE CSI EFFECT? • Trial lasts from May to July 2011 • Casey is charged with first-degree murder • The closest the state comes to a direct link was a hair found in the trunk of Casey’s car • DNA test could only link the hair to Caylee’s maternal relatives • No unique characteristics were found to link the duct tape on the body with that found in the Anthony home
- 8. CASEY ANTHONY: THE CSI EFFECT? • No DNA, No fingerprints, No conviction • July 5, 2011 • Jury finds Casey Anthony not guilty or first-degree murder, aggravated child abuse, and aggravated manslaughter of a child https://www.youtube.com/watch?v=RHcwD39Zgkg
- 9. Definition and Scope • Application of science to the criminal and civil laws that are enforced by police agencies in a criminal justice system • Criminalistics and forensic science are the same field—criminalistics is more descriptive than forensic science
- 10. Criminal Law vs Civil Law • Designed to prevent citizens from harming each other • Involves actions that have been declared illegal • Always filed by the government called the prosecution • Deals with disagreements between private individuals • One person claims the other person’s actions caused him harm • The party filing the lawsuit is called the plantiff
- 11. Definition and Scope • While shows like CSI have increased public awareness, they give an unrealistic view of how the process works • “CSI effect”—the dramatization of forensic science has led people to believe that every crime scene will yield forensic evidence and procedures unrealistic expectations https://www.youtube.com/watch?v=fGc4PaLB-ek
- 12. Development of Forensics • 3rd Century China—one of the earliest recordings of forensic science • 1686—first notes about fingerprints • Late 1800s—public officials begin to apply science to the study of crime • 1893—first treatise describing the application of scientific disciplines to criminal investigation
- 13. Late 19th Century Progress • Best known figure in the late 19th century forensics was Sherlock Holmes https://www.youtube.com/watch?v=8I9pxUdZbuQ
- 14. 20th Century Breakthroughs • 1901—discovery of different blood types • 1910—pioneering work in document examination • LOCARD’S EXCHANGE PRINCIPLE – When two objects come into contact with one another, there is exchange of materials between them
- 15. Crime Laboratories • 1923—first forensic lab opened as part of the Los Angeles Police Department • 1932—FBI organized a national lab that offered forensic services to all law enforcement agencies in the country – FBI Laboratory is now the world’s largest forensic lab
- 16. Services of the Crime Lab • Physical Science Unit – Applies chemistry, physics, etc. to crime scene evidence; Experts in chemical testing; Drug ID, Soil/Mineral analysis, Trace Evidence • Biology Unit – Biologists and Biochemists; DNA profiling on bloodstains and bodily fluids, hairs & fibers • Firearms Unit – Examines firearms, discharged bullets, cartridge cases, shotgun shells, and ammo
- 17. Services of the Crime Lab • Document Examination Unit – Studies handwriting and typewriting on questioned documents; analyzing paper and ink • Photography Unit – Examines and records physical evidence; may require highly specialized photographic techniques, such as digital imaging, infrared, UV, and X-ray
- 18. Optional Services • Toxicology Unit • Latent Fingerprint Unit • Polygraph Unit • Voiceprint Analysis Unit • Crime-scene Investigation Unit
- 19. Functions of the Forensic Scientist • Analyze physical evidence AND provide expert testimony • Analyzing Physical Evidence – Physical evidence is unbiased and must undergo scientific inquiry – The scientific method is a process that uses strict guidelines to ensure careful and systematic collection, organization, and analysis of information
- 20. Analyzing Physical Evidence • When a hypothesis is validated, it can be used in a court of law • Admissibility of Evidence – Frye v. US (1923) set the Frye Standard—expert opinion based on scientific technique is admissible only where the technique is generally accepted as reliable in the scientific community – The Federal Rules of Evidence (1973)—offers more flexible standard for admitting scientific evidence • Assigns the trial judge the task of ensuring that an expert’s testimony rests on a reliable foundation and is relevant to the case
- 21. Providing Expert Testimony • Forensic scientists are often called to testify about their methods or conclusions • An expert witness is an individual whom the court determines to possess knowledge relevant to the trial that is not expected of the average person – Must be able to explain their methods and conclusions to non-scientists • The expert must stick to the evidence—no matter what direction it may lead
- 22. Training in the Proper Recognition, Collection, and Preservation of Physical Evidence • If proper recognition, collection, and preservation of evidence does not occur, it doesn’t matter how fancy the lab is or how qualified the forensic scientist is • Forensic scientists participate in training law enforcement personnel in the proper recognition, collection, and preservation of physical evidence