forensic science one

forensic science

the application of science to law

1. death

2. forgeries

3. negligence

4. kidnapping

5. rape

6. fraud

7. assault

what does forensic science deal with?

1. solving crime

investigators solve crime with: witness, interviews, and confessions 

what does forensic science not involve? and why

expert witness 

only witness, in a court case, that is allowed to give opinion on their specialty 

• elected official

• must be a registered voter in county

• must obtain state mandated week long class and pass test or loss of position

describe coroner

• appointed position

• 1877 Massachusetts adopted official state wide

• held by licensed physician in state

• usually specialized in forensics

• meet requirements of particular state, city/county

describe medical examiner

1. forensic investigator

2. autopsy technician

3. pathologist

4. histologists

5. legal

6. photographer

7. supplemental/secretarial

name medical examiner’s staff

1. toxicology

2. trace evidence

3. serology

4. finger printing

5. ballistics 

what are the divisions of lab

toxicology

aspect of drugs in the body

controlled substances 

deals with pills/drugs themselves and quantity

trace evidence

evidence at scene

how unique something is

serology

blood

ballistics

guns

1. forensic odontology

2. neuropathology

3. forensic anthropology

4. forensic engineering

5. forensic entomology

what are the support evidences?

true

t/f: any physician in state can do natural cause of death; coroner/med examiner can do anything unnatural

1. pneumonia

2. congestive heart failure 

3. arteriosclerotic cardiovascular disease 

4. hypertensive heart disease 

5. gun shot wound

6. dementia 

7. renal failure 

give examples of cause of death

1. natural

2. homicide

3. suicide

4. accident

5. pending

6. undetermined

what are the manners of death?

• identification

• open to public

• computers since 1990

• name, age, cause and manner of death

• location of incident

• record keeper

• pic, reports toxicology

• epidemiology

• community relations

• teaching facilities

• public presentations

• under age drinking program

what are the duties of the medical examiner offices?

1. executor

2. spouse

3. children

4. parents

5. sibling

list next of kin

• no one financially responsible for NOK

• bio hazard

• cremation- common grave paupers grave

what is the disposition of unclaimed bodies?

time of death 

the time a body is found and pronounced 

autopsy

nonsterile surgical procedure

external examination and photography

what does autopsy start with?

toxicology of body fluid 

what is the second step of autopsy?

y-incision

exposes the chest plate

cut ear to ear and use fingers to separate skin from bone

how is the skull exposed in autopsy?

1. name

2. age

3. general address

4. location of incident

5. general circumstances

6. cause and manner of death 

what is public information?

• location

• description of location

• description of collision

• make, model, type, ATV reg. number

• direction of travel, speed

• safety devices (used or unused)

• vehicle defects/violations

• evidence of drugs/alcohol

what is the check list for vehicular accidents at scene?

• location of body at time of collision

• location of body after collision

• drivers, passengers, pedestrians, ect

• alcohol/ drugs (BAC/TOX from hospitals)

vehicles deceased and other involved check list

• location of drugs, medicine, alcohol

• location of paraphernalia type- smoking, drinking, injection…

• suicide note? evidence of struggling? illness?

guidelines for drug OD scene

• clothing/conditions appropriate

• visible wounds/ injections site- location and description

• injection site logical

• artificial injection site by rescue personal

• known user; dealer

guidelines for OD deceased

• nature (happy, depressed)

• personal problems (marital, family, work, health)

• behavior (changes, unusual acts, change of habits)

• previous suicide attempts/ talk of suicide 

• suicide note

• right handed/left handed

suicide investigation guidelines

• general description

• description of neck

• description of knot

• to what was this ligature attached 

guide to suicide ligature

• towel/soft material between ligature and neck

• signs of masturbation

• pornography, sexual, stimulants, mirror, ect

• clothing of opposite sex in use

• fail safe mechanisms/used/operational

guide to autoerotic suicide

• description gun, knife, bat…

• type, make, caliber, serial #

• location of weapon relative to victim

• ownership, registration, normal place kept

• disposition of weapon, casing, bullet fragments

guidelines to stabbings and gunshot

• basic guideline description

• blood stains/ patters on body, surroundings and elsewhere 

• defense wounds/ hesitation marks 

deceased in gunshot/ stabbing guideline

• evidence- note, weapon, device, drugs, poison

• PMHx- PCP, hospitals, clinics, social workers, ect.

what are the basis for suicide investigations (2)

• type of water (lake, river, ect)

• depth of water

• entry point of known

• able to swim

• clothing

• time missing/ time submerged

• alc./ drug intake

guidelines to drowning scene

• source (vehicle/heating source)

• vehicle (description)

• ignition on?

• vehicle location (garage integral/detached)

• apparatus- hose, tape, note, pillow, drugs 

• any other animals in house?

guidelines to CO poisoning

• structure

• description/type (residential, commercial, abandoned)

• construction/ brick/ wood/ # of stones

• fire source

• cause (arson, accident)

• fire location

guidelines to burns and fires

• deceased any objects caught/swallowed (nose/mouth)

• secretion (mouth/ nose ect.)

• last feeding date/time/what food

• medical: recent illnesses ect

sudden infant death syndrome guidelines

women 

2x as often 

who attempts suicide more often?

men because they choose the more violent route

who is more successful with suicide? why?

• glass

• hair (fur)

• fibers

• paint

• soil

• gunshot residue

what are the types of trace evidence?

trace evidence 

small evidence used to link victim, suspect, objects, and crime scene 

microscopes

can also be used for drugs and fire arms

what does trace evidence often use to make similarities?

• labs sections are arranged different in different labs

• different evidence could be assigned to different sections

• some labs have trace or microscopy sections

who analyzes trace evidence?

• magnifies samples

• can look more at detailed traits of a sample

• many different types for different needs  

describe what using a microscope does

can link objects to people

objects → location → victim → suspect

why is trace evidence useful?

• blood/tissue from victim

• blood/fingerprints from suspect 

• fibers from rug in van 

what trace evidence do you look for on an object(hammer)?

• blood/tissue from victim

• blood from suspect

what trace ev. do you look for on rug?

• blood/semen from suspect

• fibers from rug in van

what trace ev. do you look for on victim?

• fibers from rug or van 

• blood/tissue from victim

what trace ev. do you look for on suspect?

locard exchange principle

whenever there is contact between 2 objects, they will leave/pick up debris from the other object

difficulty comes in finding it

class

a group of objects or persons with characteristic physical evidence common to it

ex: soil and hair

can be id. as having originated with a particular person or source 

ex: fingerprints and footprints

• police officer

• crime scene investigator

• forensic scientist

  • depends on state/community

  • often 1 person to ensure consistency of labeling

who collects the ev.?

• most trace ev. classified using class characteristics

• when examining class characteristics, absolute id. not possible

• forensic scientists main objective is to give the jury an idea ab how rare category is

describe classifying ev.

true both

t/f: hair grows from follicles or tiny pockets in skin

t/f: entire surface of mammals covered with 1000s of these follicles

• length

• color

• shape

• root

• appearance

• internal microscopic features

name what characteristics of hair can be different by species

keratin 

what protein is hair primarily made of?

1. cuticle

2. cortex

3. medulla

what are the 3 layers of hair in order outer to inner

outer cuticle

strongest part of the hair; protects the inner cortex

inner cortex 

made of dead keratinized cells have been flattened or squeezed 

cuticle

protective coating made of overlapping scales; scales always point toward tip of hair

not useful in individualizing human hair

• scale case made

• clear latex on microscope slide

• hair embedded and allowed to dry before removed

• scale patter varies by species

describe scale pattern microscope procedure

anagen 

hair actively growing and materials are deposited in the hair shaft by cells found in the follicle

initial phase, may last up to 6 years root=flame shaped 

catagen

transition phase, 2-3 weeks, root=elongated

telogen

phase where hair naturally falls out, root=club shaped

1. anagen

2. catagen

3. telogen

name the 3 specific hair growth stages 

1. age

2. sex

3. race

what things can you tell from hair?

medullary index<1/3

what is the diameter of the medulla relative to the diameter of the hair shaft in humans?

medullary index>1/2

what is the diameter of the medulla relative to the diameter of the hair shaft in animals?

postmortem root band 

hair in state of decomposition, dark band may appear near root of hair

fiber

smallest unit of a textile material that has a length many times greater than its diameter; a class of material with long filaments

1. type found

2. color/variation of color 

3. # fibers found 

4. loc. of fibers at scene or on victim 

5. # dif. fibers at scene on victim or match clothing of suspect 

fiber id (5)

1. if possible, collect entire item with fiber and let lab remove fibers

   1. if not possible remove fibers from surface with clean fibers

      1. take care not to crush fibers with tweezers when handeling

2. place fiber in a pillbox or a folded piece of clean paper, taking care not kink/crush hair

collect of fiber steps

primary transfer

occurs when a fiber is transferred from a fabric directly onto a victim’s clothing

secondary transfer 

occurs when already transferred fibers on suspect transfer to victim

animal fibers

most frequently used in production of textile materials is wool, and the most common wool fibers originated from sheep

they are manufacture specific

what is special about man made fibers?