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forensics midterm
Question | Answer |
---|---|
T/F A hair consists of 2 parts: a follicle and a shaft | TRUE |
T/F The hair shaft is made up of 3 layers: an outer medulla, a cortex, and an inner cuticle | FALSE |
The region of a hair located outside of the medulla containing granules of pigment | the cortex |
hair is considered _________ evidence | class |
What is the main purpose of hair? | regulate body temperature |
Microscopic characteristics of hair are | medulla pattern cortex pigment cuticle scales (all of the above) |
6 areas hair is on body | head eyebrows/ eyelashes mustache/beard overall body (auxiliary) underarms pubic |
what part of hair contains DNA | follicle |
T/F chain of custody is the list of all the people who cam into contact with evidence | True |
T/F the first act of the first authorized personnel on the crime scene is to begin to collect evidence | False |
T/F our emotional state influences our ability to see and hear whats around is | True |
T/F thru our senses we gather info every single moment | true |
a forensic examiner must be able to | identify evidence record evidence determine significance of evidence (all of the above) |
forensic science is strictly concerned with uncovering evidence that | stands as a fact |
the first step in investigating crime | secure the scene |
criminal investigators depend on the observation skills of all involved. who is involved | police forensic scientist witnesses (all of the above) |
when evaluating eyewitness testimony, investgator must discriminate between fact and | opinion |
trace evidence includes | hair in trash fingerprints on glass blood on shirt (all of above) |
labs process all of the evidence to determine | facts of case who is innocent who is guilty (all of above) |
Locards principle states | whenever 2 pieces of evidence come in contact, material will be exchanged |
forensic in latin means | of the forum |
forensic is | application of science to law |
what are the four practices of being a good observer | observe systematically turn off filters leave final interpretation of data till later write it down |
why do our brains make it difficult to have an accurate observation (short answer) | Filter out information Fill in gaps in our perception Imperfect memories |
3 things that effect our observations (short answer) | • Emotional state • Whether you're alone or part of a group • What type/ How much activity was going on around you |
what is direct evidence? example (short answer) | Proves an alleged fact surveillance videos |
what is circumstantial evidence? example (short answer) | Used to imply a fact but can't prove it hair |
what is class evidence? example (short answer) | can be used to narrow down suspect list to a group of people ○ blood type |
what is individual evidence? example (short answer) | can be used to narrow down suspect list toa single person ○ DNA |
chemical vs. physical evidence? examples (short answer) | Chemical: needs to be altered to be figured out (blood type) Physical: can be found without altering (hair color) |
list in order steps to processing crime scene | secure crime scene separate witness search crime scene for evidence photograph, sort, package evidence question witnesses review surveillance video |
T/F experts cannot agree on a single definition for death | true |
3 ways a can die referred tp as manner of death: natural, accidental, and homicidal | false |
natural death is caused by failure of body functions due to age or disease and is least common manner of death | false |
a homicide is the death of one person caused by a minimum of 2 or more persons | false |
the longer the postmoretem interval, the more accurate the estimate of the time of death | false |
the medicacl examiner is responsible for determining the manner of death | true |
insects that arrive 1st to lay eyes on dead body | blowflies |
reason someone dies | cause of death |
specific change in body brought about the end of life is | mechanism of death |
liver mortis roughly means | death color |
pooling of blood in body, (lividity) provides a clue as to how long the person has been dead. it first begins | about 2 hours after death |
death stifness | rigor mortis |
rigor mortis is | temporary |
factors affecting rigor mortis are | temperature activity before death body weight (all of above) |
to take corpses temperature, the investigators insert thermometer into | liver |
scene marker example | a pick-up ticket for dry cleaner |
during autopsy, med examiner removes and examines the | brain heart lung (all of above) |
the 1st step of investigation is | a preliminary investigation is conducted at the death scene |
non biological evidence includes | carpet fiber a used water glass dust from crushed bricks (all of above) |
investagtors know that a victim had been dead around 12 hours if | body temp is 9.4 |
why is it difficult for forensic scientists to determine an exact time of death | it is a process and not a specific moment |
why do a corpse's muscle stiffen after death | lack of oxygen in blood |
4 tests the medical examiners will send evidence to lab for | toxicology histology neurology serology |
when is the first stage of death called, when body reaches point of no return | stoppage |
3 major phases of a death investigation | preliminary autopsy lab test |
an autopsy is conducted to determine what 4 things? | manner of death mechanism of death cause of death time of death |
what 4 things does an autopsy report include? | internal exam external exam injury list M.E. findings and opinon |
differences between manner of death, mechanism of death,cause of death | manner of death: homicidal, natural, accidental mechanism of death: specific body failure (crushing of skull/bleeding out) cause of death: reason (bat/bullet) |
T/F Bones originate from living cells called osteoplasts | false |
T/F During the development of the fetus, bones begin as soft cartilage. Osteoblasts migrate to centers of cartilage to harden bones (called ossification) | true |
T/F Osteoclasts, one type of bone cell, are specialized to creatr bone | false |
T/F Bones breath and consume evnergy | true |
when bones become injured, osteoclasts secrete | enzymes that dissolve the injured part of bone |
how many bones do babies have | 270 |
what connects joints | cartilage, ligaments, and tendons |
to distinguish between male and female pelvis, the sub pubic angle is | greater than 90 on females and less then 90 on male |
the man suture marks on a skull, marking where bones are growing together, are | the lambdoidal, sagittal, and the coronal |
when the head of a long bone has totally formed to its shaft, it is an indication of | age |
how does Osteoporosis occur? (short answer) | a lack of calcium consumed causes the osteoplasts to dissolve bones to release the calcium which weakens the bones |
3 bones that can differentiate between male and female (short answer) | pelvis, skull, femur |
3 differences between male and female skull (short answer) | female: smooth, jaw >90, less prominent brow bone male: bumpy, jaw ~90, more prominent brow bone |
one way to determine a skeleton's age (short answer) | by looking to see if the suture marks are there or have disappeared |