Question of the DAY Apr 1In which of the following ways can trace amounts of In which of the following ways can trace amounts of poison in the human body be identified.poison in the human body be identified.

A. Analysis of HairA. Analysis of Hair

B. Analysis of UrineB. Analysis of Urine

C. Analysis of BloodC. Analysis of Blood

D. Analysis of FingernailsD. Analysis of Fingernails

Chapter 6: Chapter 6: Inorganic AnalysisInorganic Analysis

Question of the Day Apr 3Question of the Day Apr 3

Qualitative inorganic analysis is used to Qualitative inorganic analysis is used to determine thedetermine the

A. number of cations in a chemical A. number of cations in a chemical solutionsolution

B. number of anions in a chemical solutionB. number of anions in a chemical solution

C. the different elements in a chemical C. the different elements in a chemical compoundcompound

D. Percent composition of each D. Percent composition of each componentcomponent

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

Earth’s most abundant elements do not include Earth’s most abundant elements do not include carbon.carbon.

¾ of the Earth’s crust is composed of Oxygen and ¾ of the Earth’s crust is composed of Oxygen and SiliconSilicon

Inorganic EvidenceInorganic EvidenceOxygen is found in water, carbon dioxide, Oxygen is found in water, carbon dioxide, and many organic compounds.and many organic compounds.

Silicon is commonly found in dusts, sands, Silicon is commonly found in dusts, sands, silicon dioxide, and silicates.silicon dioxide, and silicates.

Silicates include cement and thousands of Silicates include cement and thousands of minerals.minerals.

Quartz crystalQuartz crystal

Identification and Comparison of Identification and Comparison of Physical EvidencePhysical Evidence

Forensics requests include the analysis ofForensics requests include the analysis of explosives containing potassium chlorateexplosives containing potassium chlorate poisonous powders containing arsenicpoisonous powders containing arsenic Chemical compositions/formulations vary.Chemical compositions/formulations vary.

Potassium chloratePotassium chlorate Potassium nitrate Potassium nitrate

Trace ElementsTrace Elements

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

product.product.

Present in concentrations less than 1%Present in concentrations less than 1%

Trace elements provide “invisible” markers Trace elements provide “invisible” markers that may establish the source of a materialthat may establish the source of a material

Question of the Day April 8Question of the Day April 8Which analysis will provide the most definitive Which analysis will provide the most definitive evidence in a criminal investigation?evidence in a criminal investigation?

A. Visual comparison of two shards of glassA. Visual comparison of two shards of glass

B. Percentages of copper and zinc in brassB. Percentages of copper and zinc in brass

C. Chemical composition of Hydrochloric AcidC. Chemical composition of Hydrochloric Acid

D. Percentages of lead and magnesium in ironD. Percentages of lead and magnesium in iron

Trace ElementsTrace ElementsMatching two brass pipes to a crime sceneMatching two brass pipes to a crime scene

Brass is a combination of copper and zinc.Brass is a combination of copper and zinc.

A comparative analysis of the percent of copper A comparative analysis of the percent of copper and zinc may not be 100% conclusive.and zinc may not be 100% conclusive.

Matching percentsMatching percents

of trace elementsof trace elements

provides aprovides a

conclusive analysisconclusive analysis

to the origins of the to the origins of the

brass pipes.brass pipes.

Analysis of MaterialsAnalysis of MaterialsEvidence can also be analyzed through other Evidence can also be analyzed through other characteristics.characteristics.

Cross sections of metals and other objects can Cross sections of metals and other objects can identify their origins.identify their origins. Composition, manufacturing processesComposition, manufacturing processes

JFK AssassinationJFK AssassinationForensic investigators investigate trace Forensic investigators investigate trace elements present in soil, fibers, glass, and elements present in soil, fibers, glass, and metals.metals.

Forensics was used to investigate the death Forensics was used to investigate the death of President John F. Kennedy.of President John F. Kennedy.

Question of the Day Apr 9Question of the Day Apr 9

All of the following are true about trace All of the following are true about trace elements exceptelements except

A. Can be removed through industrial processesA. Can be removed through industrial processes

B. They exist in quantities of less than 10%B. They exist in quantities of less than 10%

C. They do not affect the function of a productC. They do not affect the function of a product

D. They provide invisible markers to identify a D. They provide invisible markers to identify a materialmaterial

Timeline of JFK’s DeathTimeline of JFK’s DeathPresident Kennedy was killed Nov 22, 1963President Kennedy was killed Nov 22, 1963

Warren Commission reconstructed the crime…Warren Commission reconstructed the crime…

1. Suspect Lee Harvey Oswald fired three shots from 1. Suspect Lee Harvey Oswald fired three shots from an Italian Carcano carbine military rifle.an Italian Carcano carbine military rifle.

2. Oswald positioned behind President’s motorcade 2. Oswald positioned behind President’s motorcade in Texas School Book Depository Building.in Texas School Book Depository Building.

3. Two bullets struck President Kennedy, 1 missed3. Two bullets struck President Kennedy, 1 missed

Timeline of JFK’s DeathTimeline of JFK’s Death

4. One bullet struck Kennedy in the back – exited 4. One bullet struck Kennedy in the back – exited through his throat.through his throat.

5. Same bullet struck Governor Connally in his 5. Same bullet struck Governor Connally in his back near his right armpit – exited his chest, struck back near his right armpit – exited his chest, struck his right wrist, and lodged in his left thigh.his right wrist, and lodged in his left thigh.

6. Third bullet fired struck President Kennedy in 6. Third bullet fired struck President Kennedy in the skull and killed him.the skull and killed him.

The Kennedy Assassination: The Kennedy Assassination: Beyond ConspiracyBeyond Conspiracy

Complete the Question Set as you watch Complete the Question Set as you watch the video.the video.

http://www.youtube.com/watch?v=Qi14A20MJbE

JFK AssassinationJFK Assassination

Forensic Analysis of the “Magic Bullet” Forensic Analysis of the “Magic Bullet” Theory.Theory.

http://www.youtube.com/watch?v=DSBXW1-VGmM

Analysis of the Kennedy Analysis of the Kennedy AssassinationBulletsAssassinationBullets

Antimony and silver concentrations are Antimony and silver concentrations are consistent in bullets/fragments recovered from…consistent in bullets/fragments recovered from…

* Measured in PPM (parts per million)* Measured in PPM (parts per million)

Governor Connally’s wrist and stretcherGovernor Connally’s wrist and stretcher

President Kennedy’s skullPresident Kennedy’s skull

Ballistics EvidenceBallistics EvidenceBullet Deformation occurs due to impact forces occurs due to impact forces acting against the momentum of the bullet.acting against the momentum of the bullet.

Factors that affect the percent of deformation Factors that affect the percent of deformation includeinclude Initial velocity of bulletInitial velocity of bullet Density of object being struckDensity of object being struck Loss of bullet velocityLoss of bullet velocity

after first impactafter first impact Angle of impactAngle of impact Composition of bulletComposition of bullet

Ballistics EvidenceBallistics Evidence

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

Emission Spectrum of ElementsEmission Spectrum of Elements

Emission spectrum – light emitted from a source Emission spectrum – light emitted from a source and passed through a prismand passed through a prism Separated into its components or frequenciesSeparated into its components or frequencies

Continuous spectrum – all color blend into a single Continuous spectrum – all color blend into a single bandband

Line spectrum – colors show as single colored linesLine spectrum – colors show as single colored lines Separated by black areasSeparated by black areas

Carbon Arc Emission Carbon Arc Emission SpectrometrySpectrometry

Obtains and records the line spectra of elements.Obtains and records the line spectra of elements.

1. Heat vaporizes and excites atoms of a specimen.1. Heat vaporizes and excites atoms of a specimen.

2. Light collected by a lens.2. Light collected by a lens.

3. Focused on a prism.3. Focused on a prism.

4. Separated frequencies recorded on photo plate.4. Separated frequencies recorded on photo plate.

Identifying Class EvidenceIdentifying Class Evidence

Bullets and Glass fragmentsBullets and Glass fragments Paint, plasticsPaint, plastics

Compositional differences in trace elementsCompositional differences in trace elements Lead-based bullets contain…Lead-based bullets contain… Copper, arsenic, silver, antimony, and cadmiumCopper, arsenic, silver, antimony, and cadmium

Individual evidence can be presented in a court Individual evidence can be presented in a court of lawof law

Question of the DAY APR 25Question of the DAY APR 25The most conclusive evidence to prove that a The most conclusive evidence to prove that a bullet was fired from a specific weapon isbullet was fired from a specific weapon is

A. Gunpowder residue on the shooter’s handsA. Gunpowder residue on the shooter’s hands

B. Determine the concentration of trace elements B. Determine the concentration of trace elements from the bulletfrom the bullet

C. Compare the caliber of the bullet to the caliber C. Compare the caliber of the bullet to the caliber of the weaponof the weapon

D. Compare rifling marks on bullet to those in D. Compare rifling marks on bullet to those in barrel of the weaponbarrel of the weapon

Atomic StructureAtomic StructureElements are collections of atoms all having the Elements are collections of atoms all having the same number of protons.same number of protons.

Electron orbitals have a definite amount of energyElectron orbitals have a definite amount of energy Due to number / set path of electronsDue to number / set path of electrons

Excited State Excited State – movement of electrons to higher – movement of electrons to higher levels when heat/light absorbedlevels when heat/light absorbed

Emission of light causes electrons to drop back to Emission of light causes electrons to drop back to lower energy level.lower energy level.

ATOMIC STRUCTUREATOMIC STRUCTURE

Bohr Models – represent the electron Bohr Models – represent the electron configuration of an atomconfiguration of an atom

First electron shell First electron shell 2 electrons 2 electrons

All other shells All other shells 8 electrons 8 electrons

Valence shell Valence shell is the outermost shellis the outermost shell May be filled (has 8 electrons)May be filled (has 8 electrons) Atom is stable and does not reactAtom is stable and does not react

BOHR MODELSBOHR MODELS ALUMINUM (Al) SODIUM (Na)

RadioactivityRadioactivityRadioactivity – emission of radiation from unstable Radioactivity – emission of radiation from unstable nuclei of some isotopesnuclei of some isotopes

Three types of radiationThree types of radiation

Alpha Particles Alpha Particles – He atoms– He atoms

Beta Particles Beta Particles – electrons– electrons

Gamma RaysGamma Rays – – HEHE electromagnetic radiation electromagnetic radiation

Neutron Activation AnalysisNeutron Activation Analysis

1. Bombard sample with neutrons1. Bombard sample with neutrons

2. Neutrons react with nucleus of an atom2. Neutrons react with nucleus of an atom

3. Sample will decay into another type of 3. Sample will decay into another type of atomatom Different elements are identified as they Different elements are identified as they

decaydecay

Neutron Activation AnalysisNeutron Activation AnalysisAdvantage – nondestructive method for Advantage – nondestructive method for identifying and quantitating trace elementsidentifying and quantitating trace elements

Disadvantage – very expensive and regulatedDisadvantage – very expensive and regulated Requires a nuclear reactorRequires a nuclear reactor

X-Ray DiffractionX-Ray DiffractionExplains how elements are combined into Explains how elements are combined into compounds.compounds.

Diffraction Patterns Diffraction Patterns – series of light and dark bands– series of light and dark bands

Only used with solid crystalline materialsOnly used with solid crystalline materials Applies to 95% of inorganic compoundsApplies to 95% of inorganic compounds