1 Forensic Science

2 Table of Contents: 1)Introduction 2)Crime Scene 3)Physical Evidence 4)Physical Properties 5)Organic Analysis 6)Microscopes 7)Hair, Fibers, and Paint 8)Drugs 9)Forensic Toxicology 10)Serology 11)DNA 12)Fingerprints 13)Arson and Explosives 14)Firearms and Impressions 15)Document and Voice Analysis Examination 16)Internet Investigation

3 1. Introduction Terms to Know Definition of Forensic Science Science Breakdown Founding Scientists Units of Forensics Labs Functions of a Forensic Scientist 3

4 Terms to Know: Algor mortis Livor mortis Rigor mortis Autopsy Expert Witness Locard’s Exchange Principle 4

5 Definition of Forensic Science It is the application of science to those criminal and civil laws that are enforced by police agencies in a criminal justice system. 5

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7 Founding Scientists Mathieu Orfila ( )  Father of toxicology.  First to detect poisons in animals. Alphonse Bertillon ( )  Developed the science of anthropometry, the taking of body measurements as a means of distinguishing people. (This was replaced later by fingerprinting). Francis Galton ( )  First to look into fingerprinting.  1892 wrote “Finger Prints” which talked about the science of fingerprinting. Leone Lattes ( )  Developed the technique for determining the blood type of a sample of dried blood. Calvin Goddard ( )  First to refine the science of bullet comparison. Albert Osborn ( )  Authority on authenticating documents. Walter McCrone ( )  Perfected the use of the microscope in investigation. Edmond Locard ( )  Perfected the use of scientific method in today’s labs.  Locard’s Excange Principle McCrone 7

8 Units of the Forensics Lab Basic Units Optional Units Other Units 8

9 Basic Forensics Units Physical Science Unit  Chemistry, Physics, and Geology  Work with drugs, glass, paint, explosives, and soil. Biology Unit  Biology and Biochemistry  Work with DNA, blood, body fluids, hair and fibers, and living organisms (animals to plants). Firearms Unit  Physics and Chemistry  Works with gun, bullets, and trajectory plans. Document Examination Unit  Physics, Chemistry, and Biology  Works with examining handwriting, typewriting, paper and ink documents. Photography Unit  Physics and Chemistry  Works with photos, X-ray, UV, infrared, and digital imaging. 9

10 Optional Forensics Units Toxicology Unit  Works with body fluids determining the effects of drugs and poisons. Latent Fingerprinting Unit  Works solely with fingerprinting and identifying people according to those prints. Polygraph Unit  Works with validating statements made using a polygraph machine. Voice Printing Analysis Unit  Works with identifying sounds and voices on recorded media. Evidence Collection Unit  This unit works only with the collection of evidence from a crime scene. 10

11 Other Units Forensic Pathology  Works with identifying dead bodies and reason for death. Forensic Anthropology  Identifies human skeletal remains. Also tries to reconstruct from the remains the physical appearance of the deceased. Forensic Entomology  Works with the use of insects to find the timeline of the death. Forensic Psychiatry  Tries to “get into” the criminal mind to understand why they did what they did or what their next step will be. Forensic Odontology  Identifies the person by their teeth or bite marks. Ted Bundy page 2 Forensic Engineering  Reconstructs the crime scene. 11

12 Functions of a Forensic Scientist 1. Analyze Physical Evidence 2. Provide Expert Testimony 3. Constant Updating of Education 12

13 Terms to Know Introduction Steps to a Crime Scene Conducting a Systematic Search for Evidence Collecting and Packaging Physical Evidence Crime Scene Safety Legal Considerations

14 Terms to Know:  Buccal swab  Chain of Custody  Finished Sketch  Rough Sketch  Physical Evidence  Standard/Reference Sample  Substrate Control

15 Forensics begins at the Crime Scene!  If the investigator cannot recognize physical evidence or cannot preserve it for the laboratory examination then the case could fall through.

16 What is Physical Evidence?  Any object that can establish that a crime scene has been committed or can provide a link between a crime and its victim or between a crime and its perpetrator.

17 Steps to a Crime Scene: 1. Secure and isolate the crime scene.  Done by the 1 st officer on the scene. 2. Lead investigator evaluates the site. 3. Set the boundaries of where the crime occurred. 4. Locate where the perpetrator entered and exited the scene. 5. Conduct a systematic examination of the scene. 6. Record the scene. (photos/sketches/notes)

18 Photographing a Crime Scene  Photos are taken at different angles to get a clear view of the scene.  If items/people are removed that should be noted on the photo.  Photographs are taken of all the physical evidence that is collected.  Digital cameras are the best since you can piece together several pictures for a 3D view.  Video cameras are good for the added bonus of sound records.

19 Sketching a Crime Scene  Rough Sketch Draft representation of all the essential information and measurements at a crime scene. Drawn at the scene.  Finished Sketch Precise drawing of a crime scene drawn to scale. (Drawn with care) Use of computer CAD programs is most common.

20 Rough Sketch

21 Finished Sketches

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23 Conducting a Systematic Search for Evidence page 51 Start Finish Spiral Search Grid Search Strip / Line Search Quadrant / Zone Search

24 Conducting a Systematic Search for Evidence  After the search is conducted at the scene more evidence can be collected off of the suspects.  If there is a dead body evidence is looked for on their clothing, fingernail shavings, head/pubic hairs, vaginal/anal/oral swabs, and hand swabs for GSR.

25 Collecting and Packaging Physical Evidence  Must be done correctly and accurately to maintain the integrity so that the evidence can prove the case.  Each piece of evidence must be separately collected and packaged See handout

26 Collecting and Packaging Physical Evidence  Chain of Custody List of all the people who came in possession of an item of evidence. This is very important when establishing validity in a court case.

27 Collecting and Packaging Physical Evidence  Standard / Reference Sample Physical Evidence whose origin is known and can be compared to an unknown.  Examples: Soil from a known source vs soil from crime scene. DNA from a suspect vs DNA from crime scene.  Substrate Control Used mainly in arson cases. A piece of unmarked material is used to compare to the marked material.  Example: A burnt piece of countertop is compared to a non- burnt piece of the table top.

28 Crime Scene Safety  OSHA – Occupational Safety and Health Administration Enforced that all law enforcement personnel should be vaccinated for Hepatitis B.  IAISC – International Association for Identification Safety Committee. 1. Workers must wear latex gloves (double), Tyvek shoe covers, and liquid repellent overalls when necessary. 2. Workers must wear a mask with respirator and face shield when working with scrapings or dust. 3. When scraping blood samples a separate brush should be used for each sample. 4. Red biohazard bags are to be used with identifying what is located in the bag. 5. Notes should be done with uncontaminated gloves so there is no transfer. If pens are used on the biohazard bags they are to be disposed of in the bag. 6. If the worker comes in contact with biohazard materials they are to wash with a 10% bleach solution. 7. Eating/drinking/smoking/application of makeup/perfume/deodorant is not allowed at the crime scene. 8. Yellow biohazard bags are to be used for infectious linens.

29 Legal Considerations  Warrants  Time Constraints  Personal Safety  Community Safety