Forensic Final Study Guide

Arson

• National Fire Incident Reporting System (NFIRS)

  • part of the Bureu of Alcohol Tobacco and Firearms

• Federal Emergency Management Agency (FEMA)

• Indicate arson:

  • premeditated

  • cautious with time and place

  • point of origin carefully chosen

• Motives - which are most/least common

  • Most Common: Financial gain, revenge, vandalism

  • Other motives: Political motives, thrill-seeking behavior, urban miners, drug dealers, domestic violence, pyromania

• Forensic findings - indicators of experience of arsonist

  • multiple points of origin

  • cause masked based on location

• points of origin

  • mask cause

  • provide proper fuel

• investigation

  • record point of origin based on burn patterns

  • find evidence of accelerants

  • try to arrive during fire to note flame color/pattern, injuries, witnesses

  • secure scene to avoid spoilation

  • photo before touching

  • collect debris and accelerant evidence

  • allow wet things to dry

  • store accelerants in air-tight cans

• burn patterns

  • unburned sections = accelerant poured

Bombing

• Timothy McVeigh case - what case did he cite as inspiration

  • 1995 Oklahoma City Bombing

  • frustrated w lack of promotion in military

  • anti-government

  • Waco and Ruby Ridge were inspirations

• Dirty bomb

  • bomb that scatters radioactive material to contaminate

• Evidence collection procedures

  • look for secondary bombs

  • evaluate damage

  • figure out type of explosive (pattern, point of origin)

  • figure out perpetrator profile/motives (type of bomb, warning signs)

“Who Killed Mikey” (Lecture by Jeff Wood)

• Tattoos indicating type of gang (folk nation vs. people’s nation)

  • folk nation tattoo

• Relevance of the location where Mikey’s body was found

  • Basement of a house near gang divide

• Cause of death

  • Suffocation by brick placed in her mouth was CAUSE OF DEATH

• Determining whether Mikey may have fought back

  • No broken fingernails or wounds so she didn’t fight back

• Sexual assault

  • Pipe shoved up her vagina

  • Semen not found inside her but on her underwear

• Confessions of Nevest Coleman and Darryl Fulton - issues?

  • Coleman and Fulton confessed to having a threesome with her that went wrong

  • Later said that they were beat up and forced to confess but they had no part in her rape/murder

• Clarence Neal

  • Confesses to having sex with her but not to raping her

  • No gang experts at interview to call out lies

• Currently a cold case

Forensic Entomology

• Basics - definition, use/application in forensic cases (i.e. what can entomology evidence tell investigators?)

  • Forensic entomology: where arthropod science and the legal system intersect

  • necrophilous insects: dead loving insects

  • purpose

    • postmortem interval determination

    • as the body decomposes other evidence becomes less useful and insect evidence becomes more useful

    • cause of death (bugs go to wound spot)

    • timing of abuse (age of insects in wound)

    • extract human DNA from insects

    • if body was moved (type of bug/life cycle based on environment)

    • poaching (out of season hunting) and animal abuse

    • detection of drugs/substances

  • Most important bugs

    • flies (determinant size aka grows at a fixed rate, predictable behavior, easy to determine species/age)

    • beetles (not exclusively necrophagous, development is indeterminant, less predictable)

• Timeline for insect colonization - which insects arrive first?

  • insects smell odors (gases released) of death, signal with pheromones to others, and sense bacterial signaling from body

  • blow flies arrive first

  • then flesh flies

  • then other flies in predictable patterns

  • beetles arrive after first wave of flies

• Differences seen in natural vs. traumatic death

  • Natural: bugs colonize natural body openings (ex eyes and mouth)

  • Trauma: bugs colonize wounds and semen (rape cases)

• Cases involving living people

  • Insects colonize unkempt wounds

  • poor hygiene or sexual assault (mouth, anus, genitals)

  • soiled clothing/diapers (ex of baby with unchanged diaper having flies feeding on diaper rash

  • eggs can hatch inside of people

Michael Baden - autopsy video

• Robert Curley case

  • Robert Curley, a young electrician for a university went to hospital complaining of feeling like he was on fire

  • Lab test revealed he was killed by thallium

  • Nothing was found in air or by swabbing surfaces

  • Bottles of thallium found in lab where he worked

  • Workers were unaffected but wife and daughter had small amounts of thallium in their system

  • Robert’s thermos had traces of thallium

  • Autopsy revealed hair strands that could be used to see when he took the poison at what point in time

    • hair showed that he had been being poisoned long before his death

    • largest dose was while he was still in the hospital

  • Autopsy revealed high concentration of thallium in digestive tract

  • Wife killed him for his money and confessed

Forensic odontology

• Uses

  • no two mouths are alike

  • highly resistant to destruction

  • used to identify corpses that don’t have much left (ex. Waco, WTC bombings, natural disasters, plane crashes)

• universal system

  • 32 teeth

  • types of teeth

  • disease

  • fillings, coloring

  • crowns

  • dental x-rays

• Potential problems/limitations

  • Analysis on the bite mark of an alive victim is required within 8 hours

  • wounds change over time

  • subjective science - ex Once Bitten case (Ray Krone)

• process for natural disaster search

  • look for jaw/tooth fragments

  • postmortem dental exam

  • collect antemortem records

  • put all in computer

  • compare and match via computer software

• bite marks

  • look at bruising/blood vessel damage

  • quantity/size/location

  • time of death/method/motive

• ex. Ted Bundy

  • matched unique indentation to his mouth

Glass evidence

• Use in forensics

  • different formulas in different glass manufacturing facilities

  • breakage patterns

  • types of glass (density, color, refractive index)

• Methods of analysis

  • physical features

    • pebbled, textured, frosted

    • thickness

    • markings

  • hardness

    • scratch test

  • density

  • optical

    • reflection of light

  • breakage patterns

    • random

    • second fracture pattern will not go past first fracture pattern

    • windshield glass (2 glass pieces with foil in between) will shatter and pieces will stay on foil

    • tempered glass (really strong) will shatter NOT break

• Gerber case

  • Parents complaining that their Gerber products had glass shards in them

  • Glass analysis found that the glass was not from Gerber jars

  • Biggest pieces of glass were insignificant in size
    

Soil evidence

• Forensic examination process and principles

  • types of soil

    • silt - soft like flour, soil that makes mud, easily blown away

    • loam - sand and silt with a bit of clay (used by farmers)

    • sand - gritty

    • clay - heavy and dense with water

    • gravel - loose rocks

  • ratio of material in soil (minerals, water, glass, etc.)

  • examine microscopically

  • acidity, color, consistency

  • foreign objects

  • sifting

  • spectrography

• How it can be useful for investigation

  • All soil from diff areas has diff ratios of material

  • Mud/rocks on shoes of suspects can determine place

Karen Read case

• charged with backing into her boyfriend (Boston police officer O’Keefe)

• Read claims people at house party killed him and left him to die

• Read’s BAC was too high to drive

• O’Keefe’s phone showed he never entered the house

• google search on Read’s phone read “how long to die in cold”

• couple had a fight on New Year’s and O’Keefe was dead by end of month

• O’Keefe had scratches on his arm (prosecution v defense argues if it was from fight or from animal outside)

Daniel Penny (subway killing of Jordan Neely)

• Charges

  • manslaughter

  • criminally negligent homicide

• Key arguments in trial

  • prosecution argument:

    • Placed Neely in chokehold far past when he posed a threat (6 min)

  • defense argument:

    • Pathologist hired by defense says that cause of death was not suffocation (as claimed by City Medical Examiners) but because Neely had sickle cell, schizophrenia, and had synthetic marijuana in his system

• Hung jury, then was acquitted

Computer forensics (including ch 15 from textbook)

• Define:
  ■ Proxy servers - masks IP address
  ■ Spoofing - disguising communication as coming from a trusted source
  ■ Anonymizers - hides IP address
  ■ Identity theft - use of someone else's records/information without their consent (credit cards, bank statements, etc.)
  ■ Index - every character on a computer that is indexed to be searched by the investigator

  ■ phishing - deception to obtain info

  ■ malware - mal intentioned software

• Proper procedures for securing computer evidence

  • Take photos and document scene without turning anything off (including notes with passwords/info in area, time/date on computer before moving mouse, scratches where screws might’ve been removed)

  • Unplug computer or remove batteries without turning it on/off

  • disconnect battery backups

  • shield hard drive from magnetic fields

  • use a write blocker

  • take hard drive out before turning on computer

  • copy hard drive

  • index

  • forensic software should:

    • protect system

    • recover deleted/encrypted/hidden files

    • find slack space (remnant space when old file is overwritten)

• Cases:

  • Snowden

    • Leaked top secret NSA info

    • cleared for network support and asked people for passwords to fix their account - obtained 10 high level passwords

    • currently hiding in Russia

    • worked for the CIA, Dell in NSA in Japan, Booz Allen

    • leak revealed that big companies had been handing over more info than they realized to NSA which quickened development of end-to-end encryption

  • Rosenberg

    • couple charged with spying for Soviet Union on American information like engine/nuclear weapon development

    • Convicted under Espionage Act and sentenced to death

    • Sons want parents pardoned

  • Chelsea Manning

    • former US Army solider

    • info leaked about human rights abuses by US Army

  • Assange

    • WikiLeaks founder

    • published classified docs (many war-related activity reports)

    • protestors say his charges attack free press

    • currently seeking asylum in Australia

    • Helped Manning obtain a password

    • Charged under multiple Espionage Act charges

  • Insider Threat Program - response to Manning but before Snowden

Biological/chemical terrorism

• Japan Sarin attacks

  • Japanese doomsday cult released sarin (nerve agent) liquid in public areas like subways

  • Victims died from pulmonary edema (bronchial secretions and congestion)

  • investigation: autopsy, medical reports, chromatography/spectroscopy

• Amerithrax attacks - FBI profile

  • letters with powdery substance sent to American public figures with anti-American messages

  • profiling based on writing/letter size/stamp

  • victims got lesions and flu-like symptoms

  • likely male with a background in science

  • specific strain of anthrax traced to be the kind seen in universities or in the military

• Categories for agents (A-C) and what that means - What categories are anthrax and smallpox in?

  • A - highest risk (anthrax, small pox)

  • B - threaten water/food safety

  • C - emerging threats

• Factors that affect damage from radiation

  • type/penetrating power of radiation

  • inside/outside of body

  • type of tissue exposed

  • amount and frequency of exposure

• What is a dirty bomb?

  • bomb that scatters radioactive material to contaminate

• International Chemical Weapons Convention

  • banned biological weapons

• Controlled substance schedules - least to most dangerous

  • one to five - most to least potential for harm and addiction

    • I - LSD, heroine, weed

    • II - cocaine, fentanyl, adderall

    • III - ketamine, steroids

    • IV - xanax, valium

    • V - cough medicine

• Weapons of mass destruction - basic types

  • chemical

  • nuclear

  • biological

NECC Case (fungal meningitis in epidural steroid injections across the US)

• What did they do wrong?

  • expired ingredients

  • fictitious expiration dates

  • unsterilized instruments

  • didn’t test drugs properly for sterility

  • mixed stock solutions to conceal expired products

• What illness resulted from contaminated injections?

  • fungal meningitis

    • inflammation membranes surrounding brain

    • caused by black mold

• Government agency which traced the outbreak

  • CDC (Center for Disease Control0

• Barry Cadden

  • charges:

    • convicted of 50 charges of racketeering (illegal activity as organized effort to generate profit), racketeering conspiracy, mail fraud, introduction of misbranded drugs into market and

    • acquitted on 25 charges of second degree murder

  • owner/head pharmacist of compounding center

  • defense: failed to supervise properly but did not knowingly ship contaminated drugs

• Med Watch Safety Alert issued by FDA after this case about injectable drugs/eye drops

Strangulation

• Forensic findings - differentiating between hanging & strangulation

  • strangulation will have a neck indentation that wraps all the way around

    • postural (body position obstructs airways)

    • ligature (flexible object used) - common in crimes

    • manual (application of pressure with hands) - common in crimes

  • hanging will have neck indentation that lifts where the rope lifted

• Autoerotic asphyxiation - crime scene indicators

  • sex toys

  • isolated location

  • nude

  • escape mechanism

Biological Fluids & DNA Concepts (including ch 13 and 14 from textbook)

• What samples contain DNA (what samples don’t?)

  • blood

  • saliva

  • semen

  • skin cells

  • urine

  • DON’T CONTAIN DNA: hair shafts (without root)

• Presumptive vs. confirmatory tests for blood

  • presumptive

    • luminol (hemoglobin)

    • Bluestar (contains luminol)

    • Kastle-Meyer test (phenolphthalein) (color change with hydrogen peroxide)

    • LMG (color change with hydrogen peroxide)

  • confirmatory

    • precipitin

      • uses antiserum with antibodies containing blood serum from animals injected with human blood and human blood sample

      • placed on top of each other or in separate wells and electric current is initiated (electrophoresis) to see if a precipitate forms - if it does, it is human blood

      • pros of this test: only needs a small sample, can analyse old blood, can determine animal species

    • antigen-antibody tests

      • A antigen and anti A antibody agglutinate

      • B antigen and anti B antibody agglutinate

      • AB antigen and anti A antibody or anti B antibody agglutinate

      • O antigen does not agglutinate with any antibody

    • Rhesus factor

      • amount of protein present also found in Rhesus monkeys

    • secretor: (80% of population) significant concentration of antigens in other fluids other than blood that can confirm blood type

• Sperm cell contains which type of chromosome?

  • Y-chromosome

• Semen evidence in sexual assault - timing for collection

  • semen can stay alive for 4-6 hours after assault

  • semen disappears 3 days after assault - collect before this time

• Tests for semen

  • presumptive

    • UV light

    • acid-phosphate (color change in the presence of this enzyme which is highly concentrated in semen)

    • p3O test (serological method to detect p3O enzyme)

  • confirmatory

    • high power microscope to see sperm cell shape

    • test presence of Y-chromosome

• Various DNA analysis methods

  • restriction fragment length polymorphisms (RFLP)

    • enzymes cut specific sequences wherever they are seen

    • numbers/lengths differ in different people

    • takes 6-8 weeks to get results (con)

    • requires large sample (con)

    • often damaged in large sections (con)

  • PCR

    • amplifies DNA of interest

    • manufactures complementary DNA strands by denaturing strands of sample, binding to complementary primes, and using enzymes to form new bases

    • amplicon = group of copies

    • fast (pro)

    • can give a large sample size to test on (pro)

  • electrophoresis

    • ions in solution migrate during electric current

    • used to separate short tandem repeats based on length

  • multiplexing

    • different loci simultaneously separated by electrophoresis

  • low-number-copy testing

    • increases number of PCR cycles for smaller samples

  • snapshot

    • when CODIS doesn’t provide “hit”

    • phenotyping used to make a picture of what the person probably looks like

• Legal aspects of DNA collection - law enforcement procedures

  • “matches” based on probability results are often misused in court

  • police are allowed to take DNA from suspects of serious crimes, then retest new DNA after database “hit”

• Familial DNA analysis

  • common CODIS loci between relatives

  • paternity

    • children receive 1 allele from each parent

  • mitochondrial DNA is shared with mother and maternal family and can be used to track relatives

• Golden State Killer case

  • DNA from crime scene had no CODIS matches

  • uploaded DNA to GEDmatch and tracked suspect through family tree

  • obtained DNA from suspect without his knowledge and tested it to get a match

• Basics

  • phenotype - observable characteristic of a person

  • nucleotides - chains of repeating units that compose nucleic acids

  • gene - sequence of nucleotides forming part of chromosome that provide info for protein synthesis

  • locus - position of gene along chromosome

  • allele - variant of a gene along chromosome

    • heterozygous - diff at specific locus

    • homozygous - same at specific locus

  • DNA is found in the nucleus primarily

  • RNA found in cytoplasm primarily

  • red blood cells - erythrocytes

  • white blood cells - leukocytes

  • 55% of blood = plasma - 90% water, 10% other material

  • 45% of blood = blood cells and platelets

  • STRs - repeated sequences of bases primarily found in non-coding regions

  • indexing - STR markers (repeats, locus, sequence, chromosome)

Forensic Files: know the main forensic concepts, key evidence

• The Big Chill

  • Carol had suffered with mental health issues leading up to her death so many of her symptoms were attributed to her medication (lithium)

  • She went to doctor with illness and had her blood tested which showed small amounts of ethylene glycol indicating a prolonged poisoning

  • warning signs were that her husband destroyed many of her belongings and files a day before she died, he sat wordlessly in the kitchen when the police found Carol in a coma, and his friends and family said he would often talk about antifreeze poisoning

  • Turns out she was poisoned by her husband with ethylene glycol in antifreeze poisoning

  • Tissue samples from her body after she died revealed calcium oxalate crystals in her brain and kidney, a sign of prolonged ethylene glycol poisoning

  • Husband admitted to his girlfriend of his murder while she was wearing a wire

• Once Bitten

  • Karen works at a bar and closes it but is found dead in men’s bathroom the next morning stabbed

  • had bite marks on her through her clothing

  • hairs found on her body

  • shoe impression on kitchen floor

  • Ray Krone is thought to be the murderer because his bite indentation reassembled the bites on Karen and his blood type matched that found on Karen’s clothing

  • However, the hair was of a race different from Krone’s, the shoe size of the imprint was different than his, and there were multiple inconsistencies in the bite mark

  • DNA from blood matched Kenneth Phillips and he matched the shoe size, hair race, fingerprints found on the scene, and the bite marks

• Silk Stalkings

  • flight attendant (Nancy) found dead in hotel room, hands bound with twine, sexually assaulted, and her belongings were gone

  • witness sees a man with her luggage getting into a car

  • another woman’s (Margaret) death sounds similar: she had similar wounds and was in a similar position when she died in her house that had minimal security just like the hotel where Nancy was killed

  • DNA evidence matched both cases to each other

  • fingerprint from Margaret’s faucet matched in national database to man with multiple arrests for attacking women

  • DNA obtained from cup of suspect provided enough of a DNA match to get a search warrant

  • House had a bunch of women’s lingerie and tools from murders

  • DNA testing from police department matched

  • Murderer was given a life sentence

• X-Marks the Spot

  • prostitutes bodies found on roadside - rape tests are taken for biological evidence and tire marks are found on bodies and in dirt

  • article was written humanizing one of the victims and shortly afterwards the paper receives a piece of fan mail from the killer showing a map with an x marking where another body was

  • map is compared to online maps to find the site it was taken from, Microsoft uses window of time between when the article was published and when the postage stamp was bought to figure out who accessed their site during that time

  • IP address obtained and tracked

  • search warrant obtained for the house and bloody basement, murder tools, and cars matched the tire tracks

  • DNA from soda that suspect drank in police station matched

  • killer hanged himself in prison

• Bio-Attack

  • salmonella outbreak in small town

  • specific strain analyzed and tracked to a cult that had sprayed the disease onto various restaurants’ salad bars

• Reel Danger

  • teenage boys beat up two young boys, duct taped their hands and feet, and tried to drown them in a pond

  • one of the boys pretends to drown and when the assailants leave he carries his unconscious friend to a nearby house, saving his life

  • no evidence because the bat (weapon) and the boys’ fishing rods are wet from the pond

  • woman in house nearby claims that a boy came into her house for a snack and she saw him later outside her window with a group of teenagers and a bat. she calls the police on them and they scatter

  • neighborhood canvassing identifies suspects and police get search warrants to look in their houses

  • a knife and wet shoes are found in one boy’s home

  • a drop of water from the mud on the shoes show specific algae (diatom) unique in high concentration to the body of water the boyds were drowned in