1. Chapter 6: Inorganic Analysis

2. Inorganic Evidence Inorganic compounds do not contain carbon.
Carbon Dioxide is an exception
Earth’s most abundant elements do not include carbon.
¾ of the Earth’s crust is composed of Oxygen and Silicon

3. Inorganic Evidence
Oxygen is found in water, carbon dioxide, and many organic compounds.
Silicon is commonly found in dusts, sands, silicon dioxide, and silicates.
Silicates include cement and thousands of minerals.
Quartz crystal

4. Identification and Comparison of Physical Evidence
Forensics requests include the analysis of
explosives containing potassium chlorate
poisonous powders containing arsenic
Chemical compositions/formulations vary.
Potassium chlorate Potassium nitrate

5. Trace Elements
Impurities exist in the raw materials obtained from the Earth’s crust.
May be removed through industrial processes
Often not done
Do not affect appearance or performance of a product.
Present in concentrations less than 1%
Trace elements provide “invisible” markers that may establish the source of a material

6. Trace Elements Matching two brass pipes to a crime scene
Brass is a combination of copper and zinc.
A comparative analysis of the percent of copper and zinc may not be 100% conclusive.
Matching percents
of trace elements
provides a
conclusive analysis
to the origins of the
brass pipes.

7. Analysis of Materials
Evidence can also be analyzed through other characteristics.
Cross sections of metals and other objects can identify their origins.
Composition, manufacturing processes

8. JFK Assassination
Forensic investigators investigate trace elements present in soil, fibers, glass, and metals.
Forensics was used to investigate the death of President John F. Kennedy.

9. Timeline of JFK’s Death
President Kennedy was killed Nov 22, 1963
Warren Commission reconstructed the crime…
1. Suspect Lee Harvey Oswald fired three shots from an Italian Carcano carbine military rifle.
2. Oswald positioned behind President’s motorcade in Texas School Book Depository Building.
3. Two bullets struck President Kennedy, 1 missed

10. Timeline of JFK’s Death
4. One bullet struck Kennedy in the back – exited through his throat. 5. Same bullet struck Governor Connally in his back near his right armpit – exited his chest, struck his right wrist, and lodged in his left thigh. 6. Third bullet fired struck President Kennedy in the skull and killed him.

11. Facts about the JFK Assassination
Review of events leading up to the assassination of President Kennedy.
Plausible Conspiracy Theories?

12. The Kennedy Assassination: Beyond Conspiracy
Complete the Question Set as you watch the video.

13. Can a Single Gunman Fire 3 Accurate Shots?

14. JFK Assassination Forensic Analysis of the “Magic Bullet” Theory.

15. Analysis of the Kennedy AssassinationBullets
Antimony and silver concentrations are consistent in bullets/fragments recovered from…
* Measured in PPM (parts per million)
Governor Connally
President Kennedy’s skull

16. Ballistics Evidence
Bullet Deformation occurs due to impact forces acting against the momentum of the bullet.
Factors that affect the percent of deformation include
Initial velocity of bullet
Density of object being struck
Loss of bullet velocity
after first impact
Angle of impact

17. Ballistics Evidence
Why did the “Magic Bullet” show very little deformation after striking both President Kennedy and Governor Connally?

18. Emission Spectrum of Elements
Emission spectrum – light emitted from a source and passed through a prism
Separated into its components or frequencies
Continuous spectrum – all color blend into a single band
Line spectrum – colors show as single colored lines
Separated by black areas

19. Carbon Arc Emission Spectrometry
Obtains and records the line spectra of elements.
1. Heat vaporizes and excites atoms of a specimen.
2. Light collected by a lens.
3. Focused on a prism.
4. Separated frequencies recorded on photo plate.

20. Identifying Class Evidence
Bullets and Glass fragments
Paint, plastics
Compositional differences in trace elements
Lead-based bullets contain…
Copper, arsenic, silver, antimony, and cadmium
Individual evidence can be presented in a court of law

21. Atomic Structure
Elements are collections of atoms all having the same number of protons.
Electron orbitals have a definite amount of energy
Due to number / set path of electrons
Excited State – movement of electrons to higher levels when heat/light absorbed
Emission of light causes electrons to drop back to lower energy level.

22. Neutron Activation Analysis
Radioactivity – emission of radiation from unstable nuclei of some isotopes
Three types pf radiation
Alpha Particles – composed of He atoms
Beta Particles – consists of electrons
Gamma Rays – high-energy electromagnetic radiation

23. Neutron Activation Analysis
Advantage – nondestructive method for identifying and quantitating trace elements
Disadvantage – very expensive and regulated
Requires a nuclear reactor

24. Neutron Activation Analysis
1. Bombard sample with neutrons
2. Neutrons react with nucleus of an atom
3. Sample will decay into another type of atom
Different elements are identified as they decay

25. X-Ray Diffraction Explains how elements are combined into compounds.
Diffraction Patterns – series of light and dark bands
Only used with solid crystalline materials
Applies to 95% of inorganic compounds

26. The Son of Sam Case Study
Berkowitz Part I
Berkowitz Part II

27. The Son of Sam Case Study
Part III
Part IV

28. The Son of Sam Case Study
Part V

29. Son of Sam Forensics Did David Berkowitz Act Alone? Part I
Part II