Forensics Final

What are the qualities a forensic scientist should have?

Be present, defend your findings, logical and understandable, ethical behavior, skilled in profession, and excellent speaking and writing skills.

Criminalists

analyze, compare, identify, and interpret physical evidence, then report results for use in the justice system

Crime Scene Investigator (forensic science technician)

processes crime scenes to collect and preserve physical evidence

Trace Evidence Examiner

identifies and/or compares physical evidence through chemical

Latent Print Examiner

processes and examines latent fingerprints in criminal cases

Forensic Serologist/Forensic Biologist

processes, compares, and/or identifies biological evidence in criminal cases

Questioned Document Examiner

studies handwriting and typeface on questioned documents to determine their authenticity and/or origin

Firearm Examiner

examines firearms and discharged ammunition; also conducts distance determination and tool mark examination

Forensic Entomologist

studies insects to estimate the time of death

Forensic Computer Science

collects and identifies data from computers and other digital devices

Forensic Engineering

concerned with failure analysis, accident reconstruction, and causes and origins of fires or explosions

Forensic Odontology

identifies and compares dental evidence in criminal cases

Forensic Pathology

a branch of medicine used for legal purposes and concerned with determining the cause of death

Forensic Anthropology

special sub-field of physical anthropology (the study of human remains) that involves applying skeletal analysis and techniques in archaeology to solving criminal cases

Forensic Toxicologist

examines body fluids and organs to determine the presence of drugs and poisons

What is Bertillonage?

An identification system based on body measurements, physical description, and photographs

What does Locard's Principle of Exchange state?

when a person comes into contact with an object or another person, a cross-transfer of physical evidence can occur

When was the first time DNA fingerprinting was used in a trial?

1986 with Sir Alec Jeffreys for 2 rape-murders

What is the formation of crime labs?

1923 LAPD, 1930 UC Berkley, 1932 FBI National, and 1981 FBI Research and Training

Observation vs Perception

Observation is gathering info with your senses and Perception is interpretations of those senses

What is the flow of memories being made from observation to long-term memory?

Gathering info from our senses - What we pay attention to - Perception - Short term memory- Long term memory

How can you tell if a witness/suspect is telling the truth?

Truths are consistent and lies are hard to repeat

What are effective interview techinques?

Separate the witnesses, help reconstruct, write everything down, no interjecting, ask leading questions

Innocence Project

An organization staffed by lawyers and law students who reexamine cases and provide legal assistance to convicts when there is a probability that serious errors occurred in their prosecution.

What factors affect our observations

Emotional status, amount of people, amount of activity

What is the goal of CSI?

recognize, document, and collect evidence at the scene of a crime

What is direct evidence?

Statement made under oath (testimony)

What is circumstantial evidence?

Object/material relevant to the crime (physical or biological)

What is individual evidence?

Narrows on identity to a single person or thing

What is class evidence?

Things that can only be narrowed down to a group but not a single source

What is trace evidence?

small but measurable amounts of physical or biological material found at a crime scene (hair, fingernails, etc)

Securing the Scene

Responsibility of first-responding police officer

Separating the Witnesses

Investigators will compare witness accounts

Scanning the Scene

Done by forensic examiners and Determine where photos should be taken

Seeing the Scene

Crime scene examiner needs to see the scene

Sketching the Scene

Accurate, rough sketch of crime scene

Searching for Evidence

A spiral, grid, linear, or quadrant patternshould be walked and location of evidencemarked, photographed, and sketched

Securing and Collecting Evidence

All evidence needs to be properly packaged,sealed, and labeled

What is chain of custody and why is it important?

Keeping an absolutely complete record of every person who has had access to the evidence is essential to being able to use the evidence in court.

What are the duties of the first responding officer?

Block off the scene

Who arrives first at the crime scene?

Police officers

Who makes up the CSI team

Police, CSI's, Medical, Detectives, and Specialists

What 2 items must be attached to every container of evidence?

Chain of custody and evidence log

Where are the sweat glands located in your fingers?

In the finger pads

In what layer are fingerprints made?

Basal layer

What weak of pregnancy do fingerprints form

8-10

How many deltas in a loop

1

How many deltas in a whorl

1+

How many deltas in an arch

0

What 2 things so forensic examiners look for in fingerprints?

Presence of a core and a delta

How do you perform a ridge count?

The count is made from the center of the core to the edge of the delta.

What are the different types of whorl patterns

Plain, central pocket, double loop, and accidental

What are the different types of arch patterns

Plain and tented

Loop, Radial

Thumb

Loop, Ulnar

Pinky

What are minitiae

Ridge characteristics thatimpart uniqueness that is the basis forcomparison of fingerprints

Patent fingerprints

Are visible prints transferred onto smooth surfaces by blood or other liquids.

Plastic fingerprints

Are indentations left in soft materials such as clay or wax

Latent fingerprints

Are not visible but madeso by dusting with powders or the use of chemicals.

What is the name and acromnym of the database that stores fingerprints?

Automated Fingerprint Identification System (AFIS)

What do red blood cells do?

Carry respiratory gases

What do white blood cells do?

Fight disease and foreign elements.

What do platelets do?

Aid in blood clotting and help repair damaged blood vessels.

What percentage of blood is plasma?

55%

What type of evidence is blood

Class evidence

Blood type - A

42%

Blood type - B

12%

Blood type - AB

3%

Blood type - O

43%

Rh +

85%

Rh -

15%

How can you determine the point of origin?

The shape of the drop

Who created the first DNA profile?

Sir Alec Jeffreys

What year were the different blood types discovered?

1901

What is the area of convergence?

Point of origin

What are the ways people can die?

Natural, accidental, suicidal, homicide, and undetermined

Cause of death

reason for death

Proximate cause of death

underlying cause of death

Mechanism of death

specific change in the body

Livor motris

Change in color (0-2 = no change, 2-8= purple, 8+= fixed)

What effects algor mortis?

Temperature, weight, clothing, illness, physical activity, sun espouser, TOD

What is algor mortis

The cooling of the body after death

Where is a corpses body temperature taken

Liver

What location of food mean in dead body

present = 0-2 hours

small intestine = 4-6 hours

large intestine = 12+ hours

What are the time breakdowns of rigor mortis?

0-2 = start (head to legs)

12 = most rigid

15 = starts to soften

36-48 = gone

Fresh / Initial

Autolysis, Body temp drops, Insects lay eggs, Bladder and bowels may empty

Bloating/ Putrefaction (2-10 days)

Cell autolysis begins following death, Green and purplish staining occurs from blood decomposition, Skin takes on a marbled appearance, Face becomes discolored, Skin blisters, Abdomen swells with CO2 released by bacteria in sm. intestine

Active Decay / Black Putrefaction (10-20 days)

Eventually the gas causes chest and abdominal cavities to burstand collapse, Fluids leak from body openings as cell membranes rupture -putrefaction, Eyeballs and other tissues liquefy, Skin sloughs off

Butyric Fermentation / Advanced Decay (20-50 days)

Cheesy smell from butyric acid, Corpse is drying out, Adipocere is forming, Maggots leave / beetles arrive

Dry Decay (beyond 50 days)

Hair is consumed by moths and mites and Bones are left

what species of fly arrive at the body first

blowflies

what gasses attract blowflies to the body

sulfur

when will blowflies lay their eggs

within the first few minutes

how many life stages do blowflies have

7

what colors can blow flies be

green, blue, and black/brown