1. 50. Alcohol Lecture 51. Drug Lab Part 2 52. Erin Brokovich 53. What is DNA? 54. DNA Structure – notes, model, ?s 55. DNA Lab 56. Forensic DNA Analysis 57. DNA Fingerprints – notes, picture, activity 58. Collecting and Preserving DNA Evidence 59. The Long and Short of DNA – highlighted article 60. Forensic Tools Crossword 61. Ballistics Lecture 62. Firearms 63. Bullet Markings

2. #53 What is DNA? #53 What is DNA? Pages 361 – 366 & Internet Thousands of genes are arranged on… The gene is the… Genes instruct our body cells to… 1950s – Watson and Crick… DNA is a polymer which is… DNA is made up of repeating units of… DNA directs the production of… What is the human genome? Research: What is the Innocence Project? Research: Significance of Maryland vs. King with regards to DNA evidence.

3. #54 DNA STRUCTURE DNA is found in all cells (nucleus) Double helix Made up of nucleotides – 3 parts: phosphate Deoxyribose Differing nitrogen bases AT and CG (base pairing) inside of DNA molecule (the rungs) Antiparallel Rosalind Franklin Watson and Crick – won Nobel Prize for discovery of DNA structure

4. Answers to the Pre-Lab 1. deoxyribose nucleic acid 2. True 3. brought out of the solution so it can be seen 4. lysate: pink liquid containing strawberry DNA 5. interface: where DNA meets liquid during the precipitation process 6. color: white shape: double helix solubility: dissolves in water, not alcohol charge: negative pH: determine this using pH paper

5. 1.How was DNA evidence used to prove that Dr. Sam Sheppard did not murder his wife? 2.Why wasn't this evidence used when the case first went to court? 3.Why do you think the DQA1 test was chosen for DNA analysis in this case, instead of another, more powerful genetic test? 4.If the blood trail left at the murder scene wasn't Marilyn's or Sam's, whose blood might it have been? 5.If you were a juror on this trial, would you be convinced by the DNA evidence? http://www.pbs.org/wgbh/nova/education/body/forensic-dna-analysis.html

6. 1.How was DNA evidence used to prove that Dr. Sam Sheppard did not murder his wife? 2.Why wasn't this evidence used when the case first went to court? 3.Why do you think the DQA1 test was chosen for DNA analysis in this case, instead of another, more powerful genetic test? 4.If the blood trail left at the murder scene wasn't Marilyn's or Sam's, whose blood might it have been? 5.If you were a juror on this trial, would you be convinced by the DNA evidence? http://www.pbs.org/wgbh/nova/education/body/forensic-dna-analysis.html

7. http://www.pbs.org/wgbh/nova/education/body/create-dna-fingerprint.html

11. Making a DNA Fingerprint 1) Collect cell sample 2) Extract DNA from cells 3) Cut DNA into pieces Restriction enzymes Restriction enzymes: work like scissors to cut DNA at certain locations

12. 4) Electrophoresis occurs Gel ~Gel: acts as strainer, allows DNA to move through it, small pieces go farther Electrophoresis ~Electrophoresis: the process of moving molecules with an electrical current DNA is negatively charged so it will move to the + end of the machine ~DNA is negatively charged so it will move to the + end of the machine

13. Southern Blotting 5) The pattern in the gel is transferred to a nylon membrane: Southern Blotting 6)Adding a radioactive DNA probe will bind to specific sequences of DNA (stain) 7) X-ray film is used to detect radioactive pattern

14. #58. Collecting and Preserving DNA Evidence Read pages 390 – 395 and take notes on: – How many cells are needed to obtain an STR profile – Low copy number – Epithelial cells – Table 13-2 (know cigarette, hat/mask, envelope, can, fingernail, sheet) – First step in collecting evidence – Packaging and storage of evidence – Evidence in soil – Contamination – Steps to minimize contamination

15. #58. Collecting and Preserving DNA Evidence Read pages 390 – 395 and take notes on: – How many cells are needed to obtain an STR profile – Low copy number – Epithelial cells – Table 13-2 (know cigarette, hat/mask, envelope, can, fingernail, sheet) – First step in collecting evidence – Packaging and storage of evidence – Evidence in soil – Contamination – Steps to minimize contamination

16. Ballistics Ballistics – the study of projectiles (bullets) and firearms Firearm – a weapn capable of firing a projectile using a confined explosive as a propellant. Ballistic evidence helps explain: – Type of firearm – Caliber of bullet – Number of bullets fired – Where the shooter was located – Whether a weapon was fired recently – If a firearm was used in previous crimes

17. History of firearms Chinese invented gunpowder: fireworks 14 th Century Europe: directed gunpowder down cylinder to fire a projectile Matchlock weapons: used wick to carry flame to gunpowder 16 th Century: Wheelock: used a wheel to ignite spark

18. 17 th Century: Flintlock: uses sparks from a chip or flint; allowed to fire in wet weather Muzzle-loading: user puts the gunpowder and projectile down the barrel 19 th Century: Percussion Cartridge and breech loading Revolver, semi- automatic, and automatic handguns

19. #62. FIREARMS Long guns – use 2 hands, longer barrel makes shots more accurate – Rifles: bullets; would will be small and round – Shotguns Pellets from a shot: wounds will small, superficial, widespread Slug: wounds are much larger and deep Handguns – fired with one hand – Pistols: 10 or more cartridges in clip/magazine – Revolver: 6 cartridges in a cylinder; first invented by Samuel Colt

21. Revolver Semiautomatic Fully Automatic

22. Grooves are indentations in the rifle’s barrel. The ridges (raised areas) that surround the grooves are called lands. – Leave grooves in BULLET produce the twisting that adds accuracy. This leaves a pattern on the bullet that matches the barrel pattern to a specific firearm. RiflingRifling: the arrangement of spiral grooves and lands on the inside of a rifle barrel

23. Bullets, Cartridges, and Calibers OH MY! Cartridge—a case that holds a bullet, primer powder, and gunpowder The bullet, usually of metal, is out front with the cartridge, holding the primer and propellant powders, behind. Headstamp – tells manufacturer, caliber, sometimes year headstamp

24. Caliber Bullets (and their cartridges) are named by caliber and length. Caliber —a measure of the diameter of the cartridge—by hundredths of an inch. (Europeans use the metric system- 9 mm) Common calibers include:.22,.25,.357,.38,.44,.45 A.45 caliber cartridge measures 45/100 of an inch in diameter (almost ½ an inch). Caliber also refers to the diameter of the inside of a firearm’s barrel; therefore, the caliber of ammunition should match the firearm that shoots it. If a bullet is removed from a wound or crime scene, its caliber can link it to the weapon used to fire it.

25. The inner surface of the barrel of a gun leaves its markings on a bullet passing through it. These markings are peculiar to each gun. Called striations. The gun barrel is produced from a solid bar of steel that has been hollowed out by drilling. The microscopic drill marks left on the barrel’s inner surface are randomly irregular and serve to impart a uniqueness to each barrel. #63. Marks on the Spent Cartridge Casings

26. The comparison microscope serves as the single most important tool to a firearms examiner. Two bullets can be observed and compared simultaneously within the same field of view. Not only must the lands and grooves of the test and evidence bullet have identical widths, but the longitudinal striations on each must coincide.

27. 27 Firing pin marks – appear on the rim or center of the spent cartridge – can be used to match a cartridge to a firearm Breechblock marks – produced when the cartridge casing slams backward and strikes the breechblock Extractor & ejector marks – striations Other marks

29. 29 Gunshot Residues Gunshot Residues (GSR) – Particles of unburned powder and traces of smoke – Leave traces on the hand, arm, face, hair, or clothing of the shooter and/or victim Chemical testing can detect residue even if removal is attempted Distance from victim to shooter can be determined by examining the residue pattern on the victim

30. http://hyperphysics.phy-astr.gsu.edu/hbase/traj.html Voy = sin(angle) X Vo Vox = cos(angle) X Vo Vo = original velocity