Exam 3 Flashcards
UNABOM Investigation
20 year investigation.
16 IED’s.
3 deaths, 21 injured.
UNABOM Name
Una = Universities and Airlines. Bom = Bombing.
UNABOM Timeline
#1 University of Illinois. #2 Northwestern University. Bombing Flight American Airlines #444. Professor Fischer, Vanderbilt University 1982. University of California Berkeley 1982.
American Airlines Flight #444 IED
November 1979 IED made of coffee can. Barometer/altitude switch. Coffee can prevented black powder from building pressure because it was so thin. Powder burned inside can. Smoke filled cabin and alerted crew. Did not explode.
Professor Fischer IED
Vanderbilt University 1982.
USPS mailing.
Moved fro Penn to Vanderbilt so package had to be forwarded.
Copper pipe, sink trap w/wooden plugs to keep black powder in place, wooden switch.
University Of California Berkeley IED
Room 411, Cory Hall, 1982.
Placed, not mailed, left in science hallway.
Made to look like electronic device and left in hallway.
Handle release trigger.
Gas can pipe.
CAAMS, INC IED
Salt Lake City 1987.
Placed outside computer/electronic company.
Artist rendering from eye witness.
No IEDs of 6 years because image was plastered everywhere.
Charles Epstein IED
California 1993.
Looked like a book.
Opening package triggered bomb.
Mailing label on package gave new evidence (paper, typewriter, saliva).
Thomas J. Mosser
1994.
Another label to compare to previous ones.
First time using shrapnel (nails, screws, etc.)
Death of recipient.
UNABOM Break in the Case
After Mosser’s death, FBI changed tactics.
Put ads out to ask why he did it.
UNABOMER wants LA and NY Times to publish Manifesto, they do so.
Kaczynski’s brother recognizes prose and sends in a tip.
Search for the UNABOMER
Small team sent to monitor Kaczynski.
Investigation to produce warrant, 1996.
Ruse with game warden to lure Kaczynski out of cabin while they searched his cabin.
UNABOM Cabin
10 x 10 foot cabin.
Warrant to search cabin, but not to arrest suspect.
UNABOM Evidence Found
Typewriter, Hoodie and Sunglasses, explosive material on shelves, wooden axe handles used for switches, shoes with another shoe size bolted to bottom, tin snips, stapler used to staple manifesto, screws/nails, encoded diary and code book.
IED #17 ready to mail under bed, gave cause to arrest.
UNABOMER
Kaczynski.
Mathematics degree from Harvard.
Arrested 1996.
Serology
The science of body fluid identification and characterization.
Blood, semen, urine, saliva.
More inclusive definition in forensics that the general definition of serology.
Identifies fluids, not the person they came from.
Serology Test Types
Presumptive.
Confirmatory.
Serology Initial Process
Starts with evidence from victim’s clothing, weapons, etc.
Observe evidence through ASL, microscope, etc.
Use cuttings and swabs to conduct tests.
Presumptive Tests.
Confirmatory Tests.
DNA analysis.
Components of Blood
Red and White Blood Cells: 45% of blood.
Plasma: Fluid portion of unclotted blood, 55%
Serum: Liquid portion that separates from blood when clot is formed.
Red Blood Cells
Carry oxygen.
Lose DNA when mature.
More red cells than white.
5 million per microliter.
White Blood Cells
Contains DNA.
Less white cells than red.
2,000 - 7,000 per microliter.
White and Red Blood Cell Ratio
700 - 2,500 to 1
Presumptive Test
Substance could “possibly” be something.
(“Could” be blood.)
Fast reaction, not specific, cost effective.
Confirmatory Test
Substance definitely is something.
(“Is” blood.)
Time consuming, specific, expensive.
Blood Presumptive Tests
Phenolphthalein
Hemastix
Luminol
Phenolphthalein
Common presumptive blood test. 1st test to perform. Positive result produces magenta color. Things other than DNA can react this way (grass's cholorophil). 5 second test, quickly screens items.
Phenolphthalein Process
Wet q-tip, swab sample.
Combine sample with reagents.
Result in seconds.
Phenolphthalein Mixture
Hemoglobin (sample) + Phenophthalein + Hydrogen Peroxide.
Hemastix
Common presumptive blood test.
Reacts with hemoglobin.
Dip strip into blood.
Positive reaction in seconds.
Hemoglobin
Red blood cell protein that transports oxygen and possesses peroxidase-like activity.
Luminol
Special case presumptive blood test.
Has to be sprayed on.
Used for large areas (fields, large rooms, places that have been cleaned).
Causes possible blood to glow (Flourescein).
Blood Confirmatory Test
Hemochromagen Crystals or Takayama, Crystal Test
Hemachromagen Test
Also called Takayama Test or Crystal Test.
Uses formation of crystals to indicate presence of blood.
Cannot distinguish between human or animal blood.
Ouchterlony
Identification test.
Used to determine species of animal from blood.
Test this only if you think blood is animal.
Test if substance tests positive for blood but negative for DNA.
Often used before modern DNA tests.
Human vs. Animal DNA
DNA tests only work on humans.
Ouchterlony Process
Use substrate controls (stained and unstained areas.
Load both into outer wells and add anti-human antiserum.
Precipitin band is formed when diffusing stain contains proteins recognized by molecules in diffusing antiserum
Blood Characterization
Origin: Ouchterlony.
ABO Blood Type: A, B, AB, O
Protein and Enzymes
Semen
Male reproductive cell.
Composed of spermatozoa and seminal fluid.
Spermatozoa
Cellular portion of semen.
100 million per ml.
Contains DNA.
Seminal Fluid
Fluid portion of semen.
Contains acid phosphatase (also called PSA or P30) which is unique to semen.
400x other fluids
PSA
Prostate specific antigen.
Also called acid phophatase or P30.
Found in seminal fluid portion of sperm.
Semen Presumptive Test
Acid Phosphatase/PSA/P30 turns light blue if substance is possibly semen.
Semen Confirmatory Test
P30 Test.
Microscopic Identification of sperm.
P30 Test
Confirmatory test for human semen. Antibody reaction which forms precipitant bands on test device when positive. Much like pregnancy test. C = control, T = postive result. If positive, send to DNA.
Microscopic Identification of Semen
Looks for spermatozoa.
PSA unique to seminal fluid.
Identifies sperm with with unique human sperm morphology of head and tail.
Saliva Presumptive Test
Uses amylase found in saliva, which can also be found elsewhere in the body.
Saliva Testing
Different from blood and semen tests.
Only has presumptive tests.
DNA comes from skin cells shed from sides of mouth.
Amylase Test Process
Starch agar is flooded with Gram’s iodine.
Iodine reacts with starch to form dark blue colored complex.
Clear areas around sample indicate starch breakdown due to presence of amylase.
Amylase
Enzyme used to presumptively identify saliva.
Can be found in other places in the body.
Blood Preservation
Tubes with purple tops indicate samples that contain a preservative so that sample lasts forever and will not deteriorate.
DNA Identification Needs
Need known samples to compare to.
Samples take from blood, cheek/mouth swab.
Often requests purple-topped blood sample.
Sources of DNA Samples
Masks/Caps: Saliva from mask, sweat from cap.
Chewing Gum: Saliva.
Bandages: Skin, blood.
Chewing Gum Case Example
Ring of thieves stole their getaway cars.
Gum taken from ignition switch positively identified one.
Confessed and led police to others.
Bandaid Case Example
Bank robber covered face in bandages as disguise.
Threw them away outside bank.
DNA recovered from adhesive portion matched suspect.
Serology Protocols
Like a recipe, follow steps to get desired result.
Uses positive/negative controls to ensure accuracy.
Always test known first to make sure it’s working.
Test for both positive and negative controls before sample.
Serology Protocol Example
German “serial killer”.
Factory worker contaminated cotton swabs used in lab work.
No pos/neg controls were done to make sure they were clean.
Plant DNA
Plant material is useful due to frequent association with dead bodies or clothing.
All plants have DNA “fingerprint”.
DNA variation low in clonal plants but still useful.
Plant DNA Case Example: Trees
Rape/Murder.
Body found in brush near Palo Verde trees.
Tip of truck leaving area.
Bed of truck contained Palo Verde pods.
DNA test on pods showed they came from tree at crime scene.
Plant DNA Case Example: Moss
Man left cafe with 3 other men.
Found month later in woods a few miles away.
Small pieces of moss found on shoes and in suspect’s car.
DNA testing matched 3 types of moss growing near body.
Animal DNA Case Example: Dog Hair
Dog barked and alerted owner to intruder in bedroom.
Dog hair found on suspect’s pants.
DNA from hair matched dog.
Animal DNA Case Example: Dog Blood
Suspect and dog attacked victim.
Dog slashed with knife during attack.
Dog blood found next to victim.
DNA from dog blood matched suspect’s dog.
DNA Solutions
Private lab.
Contains North American Deer Registry
Holds white-tail deer registry for entire US.
Animal DNA Case Example: Deer
Goliath the Deer stolen from Miller farm, offered $100,000 reward.
4 years later similar deer Hercules found on Spence farm 50 miles away.
Shed antlers from Goliath compared to Hercules analyzed by DNA Solutions showed it was the same deer
DNA
Biological molecule. Responsible for hereditary traits or genetic coding. Common to all living organisms. Found in nucleus of cells. Unique in an individual.
DNA Composition
Made up of nucleotides.
32 billion nucleotides in 23 pairs of chromosomes.
Forms double helix.
Total amount of DNA found in cell is called the genome.
Genome Composition
Human genome made up of 23 pairs of chromosomes.
Each parent passes down one copy of each chromosome.
Gender Identification
Determined by sex chromosomes X and Y.
XX: Female.
XY: Male.
XY are different sizes, unlike the other chromosomes.
Chromosomes
23 pairs of chromosomes make up the human genome.
1-22 matched pairs of same size.
23 is sex chromosome, with XY having different sizes.
DNA Analysis Process
DNA Extraction.
DNA Quantification.
DNA Amplification.
DNA Genetic Analyzer.
DNA Extraction
Chemically breaks cells open to release DNA.
Purifies DNA and removes contaminates (dirt, oil, etc.)
Automated.
Important and vital first step.
DNA Quantification
Determines DNA quantity and quality.
(Different variables can degrade DNA like time and temperature).
Will only report human DNA.
DNA Amplification
Using sample DNA, millions of copies are made.
Uses PCR.
True milestone in biology/serology.
Works for all species.
Uses both crime scene and reference samples.
PCR
Polymerase Chain Reaction.
DNA molecule copy machine.
Takes place in small tube and only requires ~20 cells to produce DNA profile.
Developed by Kary Mullis, Nobel Prize in Chemistry 1993.
First used in forensics in 1992.
PCR Process (Simple)
Takes template strand and adds building blocks (ATCG).
Adds DNA enzyme polymerase to make copies.
Small snipets called primers (physical address) indicate where amplification is to occur.
13 different primers analyzed to create DNA profile.
Genome
The total amount of DNA found in a cell.
One complete set of genetic instructions needed to create an organism.
Is NOT the same as a DNA profile.
DNA Profile
Small but discriminating part of the genome.
Does not describe the entire person, but enough to identify them individually.
PCR Process (Detailed)
In each round of PCR, nucleotides separated using heat, and each becomes template for new nucleotides.
Cooling allows polymerase to pair new nucleotides with template strands.
STR Definition
Short Tandem Repeats. Non-coding sections of human genome. "Junk" DNA. Short (only 4-5 nucleotides long). STR is a DNA profile. Only found in humans.
STR Function
Physical address where primers sit.
Number of STR repeats are used to identify individuals.
High discriminating power.
Can be databased for comparison.
STR Info
Found in same place in all people, same pattern, but frequency of occurance differs.
Thousands of STRs estimated in human genome.
Same in all cells of a person and never change.
Allele
A variant of a gene (i.e. a gene for eye color can have multiple variations).
5-20% of people share the same allele at any one STR site.
STR Usage
13 (moving to 16) STRs are used to identify individuals.
All USA labs use the same STRs.
Creates legal precedence and allows them to be databased.
Multiplex
Can take multiple PCR reactions and put them in the same tube.
Can use many primers at the same time.
Genetic Analyzer
Separates PCR amplified DNA to produce DNA profile.
Profiles have peaks showing STR frequencies from both parents.
Labeled with flourescent tag.
Capillary electroporesis separates DNA.
CODIS and DNA Profiles
Suitable profiles can be uploaded to CODIS.
Only generates investigative leads - does not solve cases by themselves.
NDIS Profile Stats
Offender profiles: 11.6 million.
Arrestee profiles: 1.9 million.
Forensic profiles: 612,477.
As of April 2015.
CODIS Profile Stats
CODIS: Produced over 276,600 hits.
Oklahoma DNA Profile Stats
Offender profiles: 128,657.
Forensic Samples: 4,631.
Investigations aided: 1,995.
Two Types of Forensic DNA Analysis
Nuclear DNA: STR Analysis.
mtDNA: Sequencing.
History of Forensic mtDNA
Armed Forces DNA Identification Laboratory: Identified remains from Vietnam veterans 1993.
Forensic Science Service (UK): Identified Romanov family 1994, 1996).
FBI.
FBI mtDNA History
1992: Research begins.
1995: Validation study published.
1996 (June): Casework begins.
1996 (August): 1st US mtDNA testimony.
Mitochondrial DNA
Found outside of nucleus. Thousands of mitochondria found in single cell. Inherited from mother. Not unique to individual. Used when nuclear DNA is unavailable.
Nucleus
Houses nuclear DNA.
One nucleus per cell.
Sample Sources for mtDNA
Hair, teeth, bones.
These often have mtDNA but not nuclear DNA.
11% Factor
Even when two hairs are microscopically identical, they are still from different people 11% of the time.
Anthropological Bone Exam
Bones studied first before DNA is looked for.
If bones are not human, won’t waste time for DNA analysis.
If bones are human, mtDNA analysis moves forward.
mtDNA in Bones
mtDNA found inside bones.
Drill inside to get uncontaminated sample.
Extract mtDNA by freeze drying/pulverizing bone sample to release mtDNA.
Steps in mtDNA Analysis
- Extraction.
- Amplification (PCR).
- Sequencing.
- Sequence Comparison.
mtDNA Analysis Results
If samples do not match exactly, suspect is excluded.
If they do match exactly, person can only be included, but not individually identified.
Instead of using STR, genetic analyzer matches up 600 base pairs for comparison.
Warrens Case
Husband picked up wife from hospital with new car carrying new washing machine.
Never seen again.
Newspapers from 1929 were collected and clues collected to identify possible location of disappearance.
In 2000 divers went into lake and found remains of car, washing machine, and Mr. Warren.
Partial Match
Not all STRs match, but enough to suspect a relation.
STR Loci
Location, markers on genome used to create DNA profile.
How to Read STR Loci
STR Loci (D3S1358). D: Chromosome (3). S: Location on chromosome (1358). 14,16: Number of STRs on loci, one from each parent. One number shown if STRs are the same.
Amelogenon Gene
Codes for male (XY) or female (XX).
Familial Searches
Searching for partial matches to identify possible relatives.
1/2 Exact match or more can be useful (possible father/son relationship).
Familial Search Example: Britain
Murder case searched database and found 14 year old boy with a “near match” to suspect, led police to uncle who confessed.
Familial Search Example: North Carolina
Near match found in offender database, identified brother of individual who later confessed.
Familial Search Example: Colorado
2003 rape and severe beating.
Compared recovered DNA to 3.5 million national DNA profiles. Found near match of convicted felon in Oregon.
Grim Sleeper Case
California’s familial DNA search program identified culprit in 2008.
Legality of Partial Matches / Familial Searches
Prior to 2006, the release of partial match information was prohibited.
Left up to individual states, OK has no law at all.
No current federal regulations.
Nuclear DNA
2 copies per cell.
~ 3 billion base pairs.
Can identify individuals.
2x23 chromosomes, one copy from each parent.
DNA Test Order
Phenopalene (presumptive).
Hemachromagen (confirmatory).
STR (DNA profile).
mtDNA Structure
Single, circular unit (~16,000 base pairs).
2 Hypervariable regions (hv1 and hv2) w/600 base pairs.
Much of DNA is similar in everyone, so only look at the ones that have high discriminating power.
mtDNA vs. Nuclear DNA Analysis
Sequence vs. Length Variations.
DNA Labs
170-180 public labs connected to CODIS do nuclear DNA testing.
Only 4 do mtDNA testing.
mtDNA Disadvatages
Longer, more expensive, and less discriminating.
Can’t handle contamination and mixed samples.
