Observations Flashcards
Forensic science
application of scientific knowledge to legal questions
What does a forensic investigator do?
Observe, interpret, and report observations clearly
Observation
what a person perceives using his or her senses
Perception
info received from the senses
Perception elements
Limited
Faulty
Not always accurate
Not always reflective reality
What influences our observations?
Filtering information
Filling in the gaps
Applying previous knowledge to situations
Witness observations are affected by
Emotional states
Alone or with a group
Number of people or animal
Type of activity and how much activity
Eyewitness accounts vary based on
Level of interest Stress Concentration The amount and kind of distractions Prejudices Personal beliefs Motives Lapse in event
How to be a good observer?
- Examine systematically
- Look at everything
- Don’t make conclusions until all data has been gathered
- Document everything
Skills of a forensic scientist
Analytical skills
Deductive reasoning
Deductive reasoning
deriving a conclusion from the facts using a series of logical steps
Locard’s Principle of Exchange
Intensity
Duration
Nature
Types of evidence
Direct
Circumstantial
Direct evidence
first hand observations (confessions, eyewitnesses, video recording)
Circumstantial
indirect evidence that can be used to imply a fact but that does not prove it (trace evidence)
Class evidence
narrows an identity to a group of persons or things
Individual evidence
narrows an identity to a single person or thing
Trade evidence
transferred between people, objects, or the environment
Seeing the scene
taking pictures and videos
unit of measure
point of reference
Scanning the scene
looking through the scene & observing to find evidence
Separating witnesses
separate eyewitnesses from other eye witnesses
Securing & collecting evidence
packets, envelopes, and bags
chain of custody
Securing the scene
caution tape to make a perimeter
first responder is blocking off the scene
securing a log of people at the crime scene
trying to not tamper evidence
Searching for evidence
can use tools
divide people into different areas
evidence markers
start from the outside into the inner
Sketching the scene
bird’s eye view
units of measures (scale)
compass rose
triangulation & rectangulation (point of references)
