CRJS 370 Final Exam | Pritchard

Fingerprinting purposes

-identifications of suspects

- identification of people

Fingerprint types

- patent

- plastic

- latent

- exemplar

Fingerprint types: Patent

3d fingerprint that is easily observable, transferred by a substance onto a surface (normally in like blood or dirt and stuff)

Fingerprint types: Plastic

3D impressions left in soft materials (like wax, clay, soap), also easily seen

Fingerprint types: Latent

fingerprint from oils or sweat; cant see normally but can be lifted using powders

Fingerprint types: exemplar

Finger prints taken from bookings and for other public record

Ridge Characteristics: Ridge ending

little line stopping short

Ridge Characteristics: short ridge

little random line not connected to anything else; dot

Ridge Characteristics: bifurcation

line that is divided into two like a fork in the road

Ridge Characteristics: enclosure (island)

small line island in a split ridge, looks like an eye

Typology of fingerprints: Loops

Two types: Ulnar (runs in the direction of the pinky finger) and Radial (runs in the direction fo the thumb)

- 60-65%

- double loop (yin and yang)

Typology of fingerprints: Arches

only 5%

make a tent like shape, plain

- degree of pattern is rounded or greater than 90

- no delta

Typology of fingerprints: Whorls

30-35%

a circle lmao

- plain

• central pocket loop

• double loop

• accidental

- look for 2 deltas around the core

Childrens finger prints

disappear quickly bc bodies secrete less oils

adermatoglyphia

genetic disorder that causes a person to not have fingerprints

Positive identification

- primary classification

- ridge characteristics

- relation of characteristics

Latent prints: how to collect

- powders

- iodine fuming (sublimation)

- ninhydrin

- superglue fuming

- fluorescence

- alternative light source

forensic biometric purposes

- biometric matching

- biometric identification

physiological biometrics

• fingerprints

• palm

• hands

• veins

• iris

• retina

• facial

behavioral biometrics

• handwriting

• keyboarding

• voice recognition

• gait (the way a person walks)

biometric system process

1. enrollment (capture and store)

2. extraction (equations and algorithims)

3. template generation (recollection and access)

iris scanning

• Eye color

• Muscle definition

• Visible light capture 

• NIR capture (700-900 wavelength)

• Safe, acceptable distance

facial recognition

• Ease of use

• Permanent v. impermanent features 

  • permanent = stable face features that do not change

  • impermanent = temporary aspects of the face that changes over short periods of time

• High complexity (highly complicated)

• 2D v. 3D

Next Generation Identification System (NGI)

basically a database of biometric and criminal history information

• Update to AFIS (2013 hardline resubmit)

• Advanced Fingerprint Identification Technology

• Repository for Individuals of Special Concern (RISC)

• Latent and palm prints

• Rap back

• Interstate photo system

• Facial recognition search

• Cold case / unknown deceased

• Iris (pilot program)

Forensic Toxicology

- Alcohol

- Metabolism (absorption, distribution, and elimination)

Testing for alcohol

- BAC

- Breathalyzer

- intoxilyzer

- infrared light absorption

- fuel cell detector

formula: BAC (1ml blood) = BAC (2100ml alveolar breath at 34C)

Field Sobriety Testing

SFST: horizontal Gaze Nystagmus, One leg stand, 9 Step walk and turn

- Nonstandard tests

- non test observations

- alco sensor

- legal considerations

Testing

-Blood Testing

-BAC laws

- Schmerber V California (Court clarified the application of the Fourth Amendment's protection against warrantless searches and the Fifth Amendment right against self-incrimination for searches that intrude into the human body)

- Missouri V Mcneely (case decided by United States Supreme Court, on appeal from the Supreme Court of Missouri, regarding exceptions to the Fourth Amendment to the United States Constitution under exigent circumstances.)

Toxicology: Collection

- anticoagulant

- preservative

toxicology: pH

• acid

• base (alkaline)

• neutral

toxicology screening

- gives analyst quick insight into the likelihood that a specimen contains a drug substance

• Screening tests include:

  • Thin layer chromatography

  • Gas chromatography 

  • Immunosassy 

toxicology confirmation

- verifies a postive screening test

• Confirmation tests include:

  • Gas chromatography/ mass spectrometry 

• Hair 

• Poisons

• Metals

• Carbon monoxide 

• Drug recognition expert 

Serology

The study of reactions between antibodies and antigens (basically looking at blood I guess )

Serology cont.

- blood typing

- 33 classifications

- Landsteiners A- B- O system (1901)

- A and B antigens

- RH systems (system for classifying blood groups according to the presence or absence of the Rh antigen) ((1937)

- 50 factors

- D antigen

Blood

Made of Plasma, erthrocyte (red blood cells), and serum

Antigens

Foreign material that invades the body

Antibodies

Specialized proteins that aid in destroying infectious agents

Antiserum

Blood serum that contains specific antibodies; injected to treat or protect against specific diseases.

Agglutination

clumping of red blood cells

Kastle-Meyer test

a chemical test to determine if a stain is blood (using the chemical phenolphthalein)

Luminol

A chemical that emits a blue glow when it comes in contact with blood

Bluestar Test

new reagent whose purpose is to reveal blood stains that have been washed out, wiped off or which are invisible to the naked eye.

chemical used are:

• luminol

• oxidizer

• alkaline agent

• catalyst

microcrystalline test

a test that identifies a specific substance based on the color and shape of crystals formed when the substance is mixed with specific reagents

Precipitin Test

test that distinguishes between human and animal blood

Gel diffusion

test takes advantage of the fact that antibodies and antigens diffuse or moved to one another on a plate coated with a gel medium made from a polymer called agar

Gene

- locus

- allele

- homozygous

- heterozygous

Chromosomes

threadlike structures made of DNA molecules that contain the genes

XX and XY chromosomes

Female and male respectively (chromosomes)

dominant, recessive

dominant gene in pair overrides recessive gene Ex. hair color, hearing, dimples, vision

DNA

A complex molecule containing the genetic information that makes up the chromosomes.

nucleic acids

DNA and RNA

4 nucleotides

Adenine, Thymine, Guanine, Cytosine

complementary base pairing

In DNA, T pairs with A; G pairs with C;

RNA, U pairs with A and G pairs with C

Avg Human chromosome

100 million pairs

Genomes

All the genetic material in an organism

- 23 chromosome pairs

DNA testing

DNA profiling/genetic fingerprinting

RFLP

PCR

STR

AmpFLP

Y-STR

Mitochondrial

Paternity

CODIS (Combined DNA Index System): 15 STRs

National database: 11 STRs

watches international standard

Touch DNA

Buccal swabs (confirmation sample)

mitochondrial DNA

• Mitochondrial Molecular Clock = uses the gradual accumulation of mutations in mitochondrial DNA to estimate when different species or populations diverged, acting like a genetic timer for evolution

• Haplogroups = genetic groups of people sharing a common ancestor, defined by specific mutations in their DNA, traced through either the maternal (X) or paternal (Y) line .they act like branches on a vast human family tree, revealing ancient migration patterns and origins

evaluation

• Prosecuter’s fallacy

• mixed samples

• chimeras

• Phantom of Heilbronn

• expectation of privacy

• Maryland vs. King (2013): landmark Supreme Court case that held taking a cheek swab for DNA analysis from individuals arrested for serious crimes is a legitimate, reasonable booking procedure under the Fourth Amendment

science of fire

Combustion (exothermic and endothermic reaction)

Energy

Oxidation

Ignition Temperature

Physical state of fuel

Temperature of fuel

Flash point

Pyrolysis

Flammable range

Glowing combustion

Spontaneous combustion

exothermic reaction

A reaction that releases energy in the form of heat; heat of combustion

endothermic reaction

A reaction that ABSORBS energy in the form of heat

Energy

the ability or potential of a system or material to do work

Oxidation

oxygen combines with other substances to produce new products

Ignition Temperature

temperature of fuels must be raised enough to exceed the energy barrier

Flash point

the minimum temperature at which a liquid fuel produces enough vapor to burn

Pyrolysis

the chemical breakdown of solid material where a solid fuel burns only when exposed to heat intense enough to decompose the solid into gaseous products

Flammable Range

the entire range of possible gas or vapor fuel concentrations in air that are capable of burning

Glowing Combustion

combustion occurs on the surface of a solid fuel in the absence of heat high enough to pyrolyze the fuel; fuel burning without a flame

Spontaneous Combustion

a fire caused by a natural heat-producing process in the presence of sufficient air and fuel

evidence of fire and explosion

• packaging

• substrates

• analysis

  • headspace

  • vapor concentration

Explosion

the product of combustion accompanied by the creation of gases and heat

Oxidizing Agent

chemicals that supply oxygen

Deflagration

a very rapid oxidation reaction accompanied by the generation of a low-intensity pressure wave that can disrupt the surroundings

Detonation

the creation of a supersonic shock wave within the explosive charge

Low explosives

an explosive with a velocity of detonation less than 1,000 meters per second

ex: black and smokeless powders

High explosives

an explosive with a velocity of detonation greater than 1,000 meters per second

ex: dynamite, TNT, PETN, RDX

primary explosives

a high explosive that is easily detonated by heat, shock, or friction

secondary explosives

a high explosive that is relatively insensitive to heat, shock, or friction

questioned documents

- concept

- handwriting styles

- variations

- exemplars

- authenticity

Gilbert v. California (1967)

holding: A mere handwriting exemplar, in contrast with the content of what is written, is an identifying physical characteristic outside the Fifth Amendment protection against self-incrimination.

Unites States v Mara

Holding: that the Fourth Amendment is not violated by a compelled production of "physical characteristics" (I.E. HANDWRITING) that are constantly exposed to the public.

typescript: things to consider when checking legitimacy of documents

Ink composition

Paper composition

impact/non-impact printing

Printing marks

Transmitter indentifiers

Font

questioned documents obliterations

infrared luminescence

charred documents

indented writings

photo editing

semen acid phosphatase

An enzyme found in high concentration in semen

spermatozoa

sperm cells

ogliospermia

abnormally low sperm count

aspermia

no sperm in semen

prostate-specific antigen (PSA)

blood test that measures the level of prostate-specific antigen in the blood

PERK

Police evidence recovery kit

computer forensics

The application of computer systems and techniques to gather potential legal evidence; a law enforcement specialty used to fight high-tech crime.

parts of computer

hardware with hard disk

software

motherboard with CPU

RAM

hard disks parts

partitions

bits

bytes

sectors

clusters

FAT/MFT

Computer Searches

- live data acquisition

- forensic image acquisition

Visible Data:

- data files

- swap files

- temporary files

- latent data

- slack

- deleted files

Internet Search - hardware

- cache

- cookies

-history

- bookmarks

Internet search - over the net

- IP address

- emails and messaging

Analog (1G)

the traditional method of modulating radio signals so that they can carry information - the early mobile phone system, followed by Digital networks (2G)

Broadband (3G)

a communication channel that can provide higher-speed data communication than a standard telephone circuit (2001)

Native IP (4G)

access the Internet directly, with increased speed and bandwidth

Faraday bag

shielded pouch made of conductive materials (like metallic fabric) that blocks all wireless signals from entering or exiting

Physical extraction

a duplicate of data located on a mobile device