Question of the DAY Apr 1 In which of the following ways can trace amounts of poison in the human body be identified. A. Analysis of Hair B. Analysis of Urine C. Analysis of Blood D. Analysis of Fingernails

Chapter 6: Inorganic Analysis

Question of the Day Apr 3 Qualitative inorganic analysis is used to determine the A. number of cations in a chemical solution B. number of anions in a chemical solution C. the different elements in a chemical compound D. Percent composition of each component

Inorganic Evidence Inorganic compounds do not contain carbon. Carbon Dioxide is an exception 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

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

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

Trace Elements Impurities exist in the raw materials obtained from the Earth’s crust. May be removed through industrial processes May be removed through industrial processes Often not done Often not done Do not affect appearance or performance of a product. 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

Question of the Day April 8 Which analysis will provide the most definitive evidence in a criminal investigation? A. Visual comparison of two shards of glass B. Percentages of copper and zinc in brass C. Chemical composition of Hydrochloric Acid D. Percentages of lead and magnesium in iron

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 of trace elements provides a provides a conclusive analysis conclusive analysis to the origins of the to the origins of the brass pipes. brass pipes.

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 Composition, manufacturing processes

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.

Question of the Day Apr 9 All of the following are true about trace elements except A. Can be removed through industrial processes B. They exist in quantities of less than 10% C. They do not affect the function of a product D. They provide invisible markers to identify a material

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

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.

The Kennedy Assassination: Beyond Conspiracy Complete the Question Set as you watch the video. 0MJbE 0MJbE

JFK Assassination Forensic Analysis of the “Magic Bullet” Theory. 1-VGmM 1-VGmM

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

Ballistics Evidence occurs due to impact forces acting against the momentum of the bullet. 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 Initial velocity of bullet Density of object being struck Density of object being struck Loss of bullet velocity Loss of bullet velocity after first impact Angle of impact Angle of impact Composition of bullet Composition of bullet

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

Emission Spectrum of Elements Emission spectrum – light emitted from a source and passed through a prism Separated into its components or frequencies 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 Separated by black areas

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.

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

Question of the DAY APR 25 The most conclusive evidence to prove that a bullet was fired from a specific weapon is A. Gunpowder residue on the shooter’s hands B. Determine the concentration of trace elements from the bullet C. Compare the caliber of the bullet to the caliber of the weapon D. Compare rifling marks on bullet to those in barrel of the weapon

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 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.

ATOMIC STRUCTURE Bohr Models – represent the electron configuration of an atom First electron shell  2 electrons All other shells  8 electrons Valence shell is the outermost shell May be filled (has 8 electrons) May be filled (has 8 electrons) Atom is stable and does not react Atom is stable and does not react

BOHR MODELS ALUMINUM (Al)SODIUM (Na)

Radioactivity Radioactivity – emission of radiation from unstable nuclei of some isotopes Three types of radiation Alpha Particles – He atoms Beta Particles – electrons Gamma Rays – HE electromagnetic radiation

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 Different elements are identified as they decay

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

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 Applies to 95% of inorganic compounds