2. BT05.03 Discuss the use of DNA typing and forensic anthropology in the identification process

3. A. DNA TYPING 1.What is DNA – the genetic material found within the cell nuclei of all living things a. Nucleus of cells contains RNA/DNA b. DNA = deoxyribonucleic acid c. Nucleus has 23 pairs of chromosomes made up of DNA (in mammals, the strands of DNA are grouped into structures called chromosomes) d. Within each pair, one chromosome from sperm and one from egg

4. FYI

5. 2.What makes DNA individual? a. Four chemicals: adenine, guanine, cytosine, and thymine b. Chemical strung together = DNA code

6. c. Some sections of DNA vary from individual to individual (with the exception of identical twins, the complete DNA of each individual is unique) d. Scientists can link a strand of DNA to a given individual

7. 3.Criminal investigations a. Specimens: blood, hair, bloodstained clothing – DNA fingerprints derived from evidence collected at the crime scene are compared to the DNA fingerprints of suspects. The DNA evidence can implicate or exonerate a suspect..

8. The sample is segmented using enzymes, and the segments are arranged by size using a process called electrophoresis. The segments are marked with probes and exposed on X-ray film, where they form a characteristic pattern of black bars – the DNA fingerprint. If the DNA fingerprints produced from two different samples match, the two samples probably came from the same person

9. b. Provides powerfully compelling evidence

10. DNA fingerprinting was first developed as an identification technique in 1985. Originally used to detect the presence of genetic diseases, DNA fingerprinting soon came to be used in criminal investigations and forensic science. The first criminal conviction based on DNA evidence in the U.S. occurred in 1988.

11. Generally, courts have accepted the reliability of DNA testing and admitted DNA test results into evidence. However, DNA fingerprinting is controversial in a number of areas: the accuracy of the results, the cost of testing, and the possible misuse of the technique.

12. The accuracy of DNA fingerprinting has been challenged for several reasons. First, because DNA segments rather than complete DNA strands are “fingerprinted,” a DNA fingerprint may not be unique; large-scale research to confirm the uniqueness of DNA fingerprinting test results has not been conducted. In addition, DNA fingerprinting is often performed in private laboratories that may not follow uniform testing standards and quality controls.

13. Also, since human beings must interpret the test, human error could lead to false results. DNA fingerprinting is expensive. Suspects who are unable to provide their own DNA experts may not be able to adequately defend themselves against charges based on DNA evidence.

14. In the United States, the Federal Bureau of Investigation (FBI) has created a national database of genetic information called the National DNA Index System. The database contains DNA obtained from convicted criminals and from evidence found at crime scenes. Some experts fear that this database might be used for unauthorized purposes, such as identifying individuals with stigmatizing illnesses such as acquired immunodeficiency syndrome (AIDS).acquired immunodeficiency syndrome

15. QUESTION After reading this information, if you were a juror in a murder trail and the only evidence the prosecution had to link the defendant to the crime was DNA evidence, would you find the defendant guilty of the crime?

16. B. FORENSIC ANTHROPOLOGY 1.SKELETAL ANATOMY a. 206 bones in the human body (children have 300 since they are not all fused together yet) b. Man = 12 pounds Woman = 10 pounds

17. 2.WHAT BONES SHOW a. How person lived b. Debilitation illnesses (rickets, polio, healed fractures) c. Right handed or left handed d. Clues to occupation (for instance, waitresses show signs of their arm strength in their bones: their strong side is more developed than the other side)

18. 3. QUESTIONS ABOUT SKELETAL REMAINS a. Sex: women have broader pelvis, men have a larger jaw & forehead b. Age: joints, bones, & teeth exhibit more and more wear as a person ages c. Race: nose shape and shape of the eye socket can sometimes help determine this d. Height: determined by measuring leg and arm bones e. Weight: heavier people tend to wear down certain joints in their lower body, esp. knees & ankles

20. BT05.04 DISCUSS USES OF ODONTOLOGY AND SEROLOGY STUDIES IN FORENSIC MEDICINE

21. A. ODONTOLOGY 1. Characteristics of teeth after death a. No other part last longer b. In fires, teeth usually only means to ID remains c. No two people have identical teeth

22. 2.Requirements for identification a. Need dental records b. Dentists chart five surfaces of each tooth in a grid (odontogram) c. Can also provide “bite mark” evidence

23. 3. Teeth useful in determining subject’s age

24. B. SEROLOGY 1.BLOOD TYPES a.Four types (A,B,O, and AB) b.Rh factor c.Female cells have Barr Body (found as a drumstick-shaped mass attached to one of the nuclear lobes in polymorphonuclear leukocytes in normal females (sex chromatin)

25. 2.CRIMINOLOGY a. Kastle-Meyer test to determine if it is indeed blood b. Precipitin test – determines animal or human blood c. Can determine type and gender from blood d. Provides reliable and informative evidence

26. FINGERPRINTS No two people have the same fingerprints Fingerprints are not inherited Identical twins have different ridge patterns Dactyloscopy – term used for fingerprinting

28. Three basic types: 1. latent – invisible to the eye. Formed by sweat, either from the hands themselves or by unconscious contact between the fingers and the face or other parts of the body where there are sebaceous glands. (even if a criminal scrubs his hands and dries them thoroughly, if he then puts a hand to his face or his hair, he is likely to leave a latent print on anything he touches)

29. 2. Visible – the most legible. Results from fingers stained with blood or ink or a similar medium. Is rarely found at a crime scene 3. Plastic or molded – an impression made on a soft surface such as cheese, soap or putty

30. OTHER TECHNIQUES

31. Entomology factors the presence of insects (& particularly blowflies) and their form (egg, larva, pupa, adult) can accurately calculate time of death, because different species of insects have specific generation times

32. GRID SEARCH Search pattern used for physical evidence collection, especially in large outdoor areas. String, flags, &/or tape are often used to indicate edges of search areas, or mark out grid sections

34. LUMINOL: chemiluminescent compound that, when sprayed on even amounts of blood, reacts with the iron in the hemoglobin and causes the blood spot to glow with a blue light; effective even on surfaces that have been wiped clean of visible blood.

36. STRING METHOD Bloodstain pattern analysis technique. Establishes the source of spattered blood by connecting stains along a series of straight lines, based on their shape (and thus their direction). When enough strings have been stretched in this way, they will converge towards the source of the blood.

38. CHEILOSCOPY The study of lip prints A person’s lip prints are unique Use in criminal cases is limited because the credibility of lip prints has not been firmly established in our courts

39. Five basic types used by forensic scientists are: 1.Diamond grooves 2.Long vertical grooves 3.Short vertical grooves 4.Rectangular grooves 5.Branching grooves

40. RAPE KIT: Used in cases where sexual assault is a possibility. Doctor or nurse examiner takes DNA samples to be submitted for laboratory analysis, and records any signs of bruising, cuts, abrasions, concussion, and evidence of penetration.

41. Typical samples include clothing, underwear, debris, combings and /or pulling of head and pubic hair, fingernail scrapings and/or clippings, vaginal or penile swabs and smears, anal swabs & smears, oral swabs, saliva or blood samples See Forensic Nursing video