Term 4 Forensics Test Flashcards
what is locard’s exchange principle?
every contact leaves a trace
what does forensics mean?
connected to or used in courts of law
what is a disadvantage of collecting samples for comparison?
the sample is only helpful if you have something to compare it to (e.g. a suspect’s blood)
what are the 3 main areas involved with forensic science work?
field science, medicine, and laboratory science
what is field science?
crime scene investigation (fire and explosion scenes, illegal drug labs, etc.)
what areas may be involved in field science?
- security of the crime scene
- preventing contamination
- locating and collecting evidence
- interpretation of evidence
- possible reconstruction of the event
what jobs are included in medical science?
forensic pathology, forensic medicine, forensic psychiatry and psychology, forensic odontology, and forensic anthropology
what is forensic pathology?
post mortem examinations of reported deaths (e.g. sudden/unexpected deaths, accidents, injuries, possible homicides, etc.). conclusions are then made about the cause of death
what is clinical forensic medicine?
examining victims of crime and suspects which have sustained injuries whilst committing a crime. interpretations are given about the possible causes and timing of injuries
what is forensic psychiatry and psychology?
the mental state of a suspect or victim during a crime and/or their fitness for trial
what is forensic odontology?
identifying bodies or skeletal remains from dental records, recontructing faces, and interpreting bite marks
what is forensic anthropology?
knowledge of human anatomy, which assists identification of skeletal remains
what does laboratory science include?
chemistry, biology, toxicology, ballistics, fingerprints, questioned documents, marks and impressions
what jobs are included in laboratory science?
forensic chemist and forensic biologist
what is a forensic chemist?
can have many varied roles, such as detecting and identifying illicit drugs, accelerants (arson), explosives, and gunshot residues, and trace evidences (e.g. paint, glass, fibres)
what is a forensic biologist?
primarily works on DNA profiling, where it is possible to match DNA from a scene exactly to a suspect (samples used include blood, saliva, semen, and hair)
what is toxicology?
the detection and identification of illicit and pharmaceutical drugs and poisons, interpreting toxicity levels and the effects on the functions of the body
what is ballistics?
the study of firearms and ammunition, and the identificaion of particular guns used from fired cartridge cases and projectiles. it can determine the angle and distance a gun was fired from
what is forensic entomology?
the application and study of insect biology to criminal matters.
what are the uses for forensic entomology?
while it is usually used to determine the time of death for a body, forensic entomology can also be used to detect drugs and poisons, determine the location of an incident, and find the presence and time of the infliction of wounds
how does forensic entomology help to determine the time of death for a body?
due to their extremely regular life cycles, forensic entomologists can use the insect samples on the body to track backwards and determine when the insects first began breeding. this can predict the time of death to a high level of accuracy
what is forensic serology?
primarily responsible for the detection and identification of biological material (e.g. blood, semen, saliva, urine) on physical evidence
what does fingerprint science involve?
the detection of fingerprints on a range of different surfaces, using a variety of techniques, in order to identify fingerprints and link suspects to crime scenes
what is the discipline of questioned documents?
incorporates examination and identification of handwriting impressions and machine generated documents (type writers, printers, etc.) to determine the origin of the materials (paper, ink)
what can leave marks and impressions at scenes?
implements such as bars and screwdrivers, shoe soles, and vehicle tyres
what other areas may be involved in forensic sciences depending on the circumstances?
- botany (plants)
- linguistics (language)
- engineering
- microscopy (trace evidences such as hair and fibre comparisons, or ballistics)
what kinds of documents can be forged?
banknotes, licenses, passports, or credit cards
what are some ways that you can tell if handwriting has been forged?
- the dots on the i’s and j’s are different
- the pressure of the pen is different
- the angle or slant of the writing is different
- the loops in the writing are different
- the size of the writing is different
what is chromatography?
a process used to separate mixtures by moving them through another substance (e.g. paper)
how does chromatography work?
the chemicals in a mixture are attracted to the paper differently. chemicals that are attracted to the paper strongly do not move far, whereas those that are attracted to the paper weakly move the greatest distance, therefore separating the components
what are some examples of solvents that can be used to help colours climb up the paper in paper chromatography?
water and methylated spirits
what is the core body temperature of a healthy, living human?
37 C
what is the rate of cooling for a dead body?
0.8 C every hour until is reaches room temperature
how long does it usually take for a body to cool?
within a day, although the exact conditions, such as weather and clothing, can speed up/slow down the process
what are some changes that occur in a body after death?
- skin pales
- muscles gradually get stiffer
- later on, muscles relax again and the skin discolours as the body begins to decompose
- the skin takes on a greenish appearance within 2 days of death as bacteria begin to decomopse the body
what is rigor mortis?
the condition where the muscles stiffen in a dead body
what is livor mortis?
the condition where the skin of a dead body turns a purplish-blue colour
what is pallor mortis?
the condition where the skin of a newly dead body turns pale
under what circumstances will the coroner instruct that an autopsy be performed on a dead body?
if there is doubt about the identity of the corpse oe the way that the person died