analytical skills
ability to:
-identify a concept or problem
-isolate its component parts
-organize information for decision making
-establish criteria for evaluation
-to draw appropriate conclusions
deductive reasoning
deriving the consequences from the facts using a series of logical steps
eyewitness
a person who has seen someone or something and can communicate these facts
fact
a statement or assertion of information that can be verified
forensic
relating to the application of scientific knowledge to legal questions
logical
conclusions drawn from assumptions and known facts
observation
what a person perceives using his or her senses
opinion
personal belief founded on judgement rather than on direct experience or knowledge
perception
interpreting information received from the senses
differences between observations, inferences, and perception
-observations perceive information by using the 5 senses
-inference is when you use your observations to make a hypothesis
-perception interprets information by using 5 senses
how is information processed in the brain
our brain selects the information we take in:
information from our senses--what we pay attention to---perception---short-term memory---long-term memory
5 factors that affect our observational skills
1. emotional state
2. alone or with a group
3. # of people/animals in the area
4. type of activity going on around you
5. how much activity going on around you
how reliable are eyewitness accounts
-memory fades over time, and our brain tends to fill in details that we feel are appropriate but may not be accurate: these factors decrease an eyewitness's reliability in reporting a crime
-the testimony of an eyewitness can be very powerful in persuadin
7 things that can cause eyewitness accounts to vary
1.interest
2.stess
3.concentration
4.amount/kind of distraction around you
5.prejudices
6.personal beliefs
7.motives
what is the Innocence Project
its purpose is to reexamine post-conviction cases (individuals convicted and in prison) using DNA evidence to provide conclusive proof of guilt or innocence
4 tips for being a good observer
1. examine our environment systematically
2. observe everything, no matter how small or familiar, no matter what our emotions or previous experiences
3. concentrate first and foremost on gathering all of the available information and leaving the interpret
what does a Forensic Scientist do
there first task is to find, examine, and evaluate evidence from a crime scene. also, they act as expert witnesses for prosecution lawyers
7 different jobs a Forensic Scientist could have
1.Ballistics- works with bullets and firearms
2.Pathologists- work with bodies to determine the cause of death through the examination of injuries
3.Textile experts- observes different materials
4.Blood-spatter experts- observe blood patterns on surroundi
chain of custody
the documented and unbroken transfer of evidence
circumstantial evidence
(indirect evidence) evidence used to imply a fact but not prove it directly
class evidence
material that connects an individual or thing to a certain group
crime-scene investigation
a multidisciplinary approach in which scientific and legal professionals work together to solve a crime
crime-scene reconstruction
a hypothesis of the sequence of events from before the crime was committed through its commission
direct evidence
evidence that (if true) proves an alleged fact, such as an eyewitness account of a crime
first responder
the first police officer to arrive at a crime scene
individual evidence
a kind of evidence that identifies a particular person or thing
paper bindle
a folded paper used to hold trace evidence
primary crime scene
the location where the crime took place
secondary crime scene
a location other than the primary scene, but that is in some way related to the crime, where evidence is found
trace evidence
small but measurable amounts of physical or biological material found at a crime scene
Locard's Principle
states that when a person comes into contact with an object or another person, a cross-transfer of physical evidence
the second part of Locard's principle states that the intensity, duration, and nature of the materials in contact determine the extent of
4 examples of trace evidence
1.fingerprints on glass
2.hair on your brush
3.paint chips
4.broken glass
differences between direct and circumstantial evidence
direct includes first hand observations, circumstantial is indirect evidence that is used to imply a fact but that does not directly prove it
5 professional people at crime scene
1.police officers-first to arrive
2.crime-scene investigators-document crime scene in detail and collect physical evidence
3.medical examiners-determine cause of death when a homicide has occurred
4.detectives-look for leads
5.specialists-may be consulted
7 steps of crime scene investigation
1. securing the scene: safety of all individuals at scene and preserve the evidence
2. separating the witnesses: witnesses cannot talk to each other
3. scanning the scene: determine where photos should be taken
4. seeing the scene: pictures are now taken
why is securing the scene important
because it protects the people near the scene and preserves the evidence
method in which the evidence is documented properly
the evidence log: case number, item inventory number, description of the evidence, name of suspect, name of victim, date/time of recovery, signature of person recovering the evidence, signature of any witnesses present during collection
chain of custody and why its important
Chain of custody-the individual who finds the evidence marks it for identification and bags the evidence in a plastic or paper container
The final container for the evidence is a collection bag, which is labeled with pertinent information.
The container i
how is crime-scene evidence analyzed in forensic lab
The laboratory results are sent to the lead detective. Test results eventually lead to crime-scene reconstruction.
The detective looks at the evidence and attempts to determine how it fits into the overall crime scenario. The evidence is examined and comp
why is crime-scene reconstruction sometimes used, how is it done
Crime scene reconstruction is used to determine whether the evidence matches the witness' statements. This is done by recreating the scene and seeing if what they said fits into the overall crime scenario
how can train investigators can figure out how a crime-scene has been staged by someone
If the evidence does not match the testimony of the witness then the crime-scene was most likely staged