extra midterm stuff Flashcards
Galton contribution
discovered 3 classifications of fingerprints
Lattes contribution
discovered blood types through dried blood samples
Osborne contribution
document examination
Goddard contribution
used comparison microscope to link bullets to gun
Locard contribution
every contact leaves a trace
Jefferies contribution
DNA typing
what qualifications does an expert witness need to have
knowledge
education
experience
training
credibility
entomology
uses insect activity for location
odontology
dental impressions to identify mutilated body
toxicology
detection and identification of drugs and poisons in biological specimens
anthropology
study bones for identification
pathology
autopsy
serology
identification and analysis of bodily fluids such as blood, semen, and saliva
csi
collects and preserves evidence for lab
firearms unit
examines firearms and ammunition to determine distance shot was fired from
document examination
studies handwriting and typewriting on documents to examine authenticity and source
in vitro
outside of a living organism
in vivo
inside a living organism
how is the Bertillonage system of measurement applied to suspect identification? is it reliable? why?
uses a series of measurement for identification and compares to suspect
not reliable, other people can have the same measurements
modus operandi
pattern of repeated behavior in a criminals actions relating to a crime
CSI effect
dramatization of forensic science on TV
leads to public having unrealistic expectations
Frye standard
set guidelines for determining admissibility of evidence in court
evidence must be generally accepted by scientific community
not absolute
room for variation
Frye v. US
daubert standard
daubert v. Merrell dow pharmaceutical. inc
can technique/theory be tested?
has technique been subject to peer review and publication?
techniques potential rate of error
existence and maintenance of operation standards
did theory or method attract widespread acceptance in relevant scientific community?
situation using chromatography
DNA profiling
situation using spectophotometry
testing of trace evidence
situation using gel electophoresis
DNA separation
explain the mechanism of succinylcholine in the body
skeletal muscle relaxant, used to relax muscles during surgery or when a person is on a breathing machine
blocks nerve signals to muscles
why is it important for CSI to work quickly
longer CSI waits, more evidence will tarnish or get destroyed
evidence can’t be repaired if destroyed
keep unauthorized personnel out of scene to maintain reliable evidence
acceptable forms of evidence and documentation
evidence that’s properly preserved and follows chain of custody
photographs, sketches, notes
role of lead investigator
starts investigative process
3 necessary steps for lead investigator
determines scene boundaries
establishes path of entry and exit
initial scene walk-through (gain overview of the situation, develop strategy for systematic examination and crime scene documentation)
exceptions for needing a search warrant
in pursuit of a suspect
someone needs immediate medical attention
consent
fleeing suspect
destruction of evidence
in plain sight
rough sketch
messy, original, between 2 fixed points, shows all recovered evidence
finished sketch
precise rendering of crime scene
not done at scene
drawn to scale
uses computer aided drafting
chain of custody definition
list of people that came into contact with the evidence
chain of custody importance
no confusion around who handled the evidence and clarification for who did
purpose of a reference sample
known sample to taken to compare to unknown sample for forensic comparison
proper techniques for securing evidence
wear gloves
collect fragile evidence first
package each item in a separate bag with a label saying what it is
obtain standards for later comparison
maintain chain of custody
package each piece of evidence in correct packaging for preservation
dry any wet evidence to prevent mold
touch it as little as possible to prevent degredation
4 requirements for admissable evidence
obtained legally
relevant to crime
witness must identify that the item was a part of the crime and where it came from
follow chain of custody
direct evidence
1st hand observations
eyewitnesses
video
confessions
circumstaintial evidence
implies fact, doesn’t directly prove it
JonBenet Ramsey case summary
mother found ransom note for daughter for $118,000
body found hours later in her basement
no evidence of intrusion
parents brought friends over, dad left scene, evidence destroyed
parents remain main suspects, never solved
Casey Anthony case summary
teen mother abandoned 2-year-old daughter
waited 31 days to report missing
kept partying contrantly
found not guilty
individual evidence
object with a high probability of being linked to one source
fingerprints, DNA, etc
class evidence
object with characteristics common to a group of similar object
fibers, footprints, etc.
autopsy purpose
external and internal examination of a dead body
medical dissection and examination post-mortem
when is an autopsy done
unexplained or unnatural deaths
medical autopsy
done by medical examiner
requires family consent
determines extent of disease or effects of therapy
looks for undiagnosed disease
fewer than 12% of deaths get them
forensic autopsy
done by medical examiner
aids in criminal investigation
doesn’t require family consent
sudden and violent and unexplained deaths
cause of death
reason that the person did
manner of death
relates to circumstances that led to fatal result
5 manners of death
natural causes
homicide
suicide
accidental
other
rigor mortis
stiffening of muscles after death
what happens rigor-mortis wise after death
2 hrs pm: rigor begins
small muscles stiffen
chest muscles stiffen
arms and legs stiffen
12 hrs pm: peak rigor
small muscles relax
chest muscles relax
arms and legs relax
36 hrs: rigor ends
environmental factors that affect rigor mortis
temperature
cold: slows
hot: fast
bodily movement
exercise: fast
sleep: slow
body size
fat: slows
skinny: fast
biochemistry of rigor mortis
muscles contract when myosin and actin lock in with the help of calcium
muscles remain contracted until ATP (which requires oxygen to be made) attaches to myosin and forces it to let it go
ATP pumps calcium out of cell
no ATP at death = muscles remain contracted
ends when autolysis occurs
enzymes leak out and muscles break down
autolysis
cell break down
algor mortis
cooling of body after death
role of forensic pathologist in an investigation
investigates cause, manner, and time of death
European race skeleton
oval eyes
long, narrow eyes
smooth incisors
flat uranium
Asian race skeleton
circular eye
small, rounded nose
shoveled interior incisors
flat/outward uranium
African race skeleton
square eye
wide nose
smooth incisors
outward uranium
how can you tell gender from skeletal remains
pelvis
skull
how can you tell age form skeletal remains
teeth
growth plates
cranial sutures
cranial suture
tissues that connect the skull bones
how can the presence or absence of cranial sutures determine the age of a victim
certain sutures fuse at certain ages, so it will determine the age range of the victim
livor mortis
settling of blood in areas closest to the ground
George Zimmerman case summary
martin was walking alone at night, Zimmerman saw and followed him for protection
martin saw it as a threat and shot and attacked zimmerman in defense
zimmerman charged with 2nd degree murder
what are friction ridges
skin on fingers, palm surfaces, and soles of feet formed by minutae
how do friction ridges form and when
8-12 weeks after production
ridges form based on the fetus’s position in the womb
3 founding principles of fingerprints
uniqueness
permanent
classified
what makes fingerprints unique
minutae
how many minutae are on each print
up to 150
what is responsible for the characteristics of an individual print
how minutae and ridge details are layed out
what are the two layers of skin
epidermis and dermis
which layer of skin are minutae found
dermal papillae
3 major types of fingerprints
loops
whorls
arches
two types of loops
ulnar loop: opens toward pinkie
radial loop: opens toward thumb
process of super glue fuming
add glue to a tray in a chamber
add heat source to speed up reaction
fumes react with moisture from latent residue
bonds latent deposit to surface
what does afis stand for
automated fingerprint identification system
most common fingerprint fraction? what percentage has it
1/1
25%
biometrics
advanced form of human identification
physiological biometrics
uses physical traits for identification
fingerprints, iris/retina scans
behavioral biometrics
uses behavioral traits for identification
gait, voice, handwriting, typewriting
Watson and Crick discovered
double helix model of DNA
Rosalind Franklin
took first pics of DNA
fundamental unit of heredity
genes
what 3 components make up a nucleotide
5-carbon sugar
phosphate group
nitrogen base
what types of bonds hold DNA together
hydrogen bonds between base pairs
covalent bonds on backbone
what cells don’t have dna
red blood cells
platelets
polymorphism
variations of DNA sequences between individuals
role of helicase in replication
separates DNA by breaking hydrogen bonds
role of ligase in replication
fork goes into grapes formed by DNA ligase
role of DNA polymerase in replication
adds complimentary nucleotides to DNA strand
what does rflp stand for
restriction fragment length polymorphism
what is the classification of the enzyme used in rflp and where does it cut
uses restriction enzymes or bacterial cells to cut at recognition sites
how can gel electrophoresis be used to link both a victim and a suspect to a crime
DNA is analyzed from the scene, the victim, and the suspect then compared to see if it is a match
when is PCR used
minimal evidence
how long are str segments usually
3-7 bases
what is str
short tandem repeats found in a DNA molecule
when is str usually used
when only small amts of DNA are available
what is CODIS
combined DNA index system
how many loci are used for accurate comparison in a study
13 for positive match
why are there two peaks for each locus on an str graph
one comes from each parent
why is there sometimes only one peak on a locus on an str graph
both parents have the same number of repeats on that locus
which parent is mtDNA inherited from
mother
when is mtDNA used
when nuclear DNA typing isn’t available
disadvantage of mtDNA
only narrows to maternal relations
Golden State Killer Case
responsible for 13 murders, 50 rapes, 100 burglaries minimum
also known as the East Area rapist and Night Stalker
eventually charged in 2018, 50 years after crimes, through a genealogical database that his uncle submitted DNA to
sentenced to life in prison at age 72
