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forensic science
the application of science to the criminal and civil laws that are enforced by police agencies in a criminal justice system
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criminalistics
a division of forensic science the application of scientific techniques to analyzing physical evidence in criminal cases.
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Alphonse Bertillion
1883 establishes anthropometry to distinguish one person from another, father of criminal identification.
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Hans Gross
publishes book on criminal investigation
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edmond locard
establishes first crime lab in lyon
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Locards exchange principle
- when two objects come into contact with each other there is a transfer of material
- always present but may be lost, damaged, over looked, or too small to see
- victim may leave traces of himself at the scene, on the victim, or may take away traces
- EVERY CONTACT LEAVES A TRACE
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Sir Alce Jefferys
develops first DNA profile test @ University leicester
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Crime Labs Ohio BCI structure
Chemistry section
identify drugs or explosives residue
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Crime Labs Ohio BCI structure
Trace Section
Hairs and Fibers, foot wear impressions and tire impressions gun shot residue
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Crime Labs Ohio BCI structure
DNA/forensics biology
identification of stain like blood, seman, saliva, urine, feses, CODIS
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Crime Labs BCI structure
firearms section
bullets and caseings also tool marks anything fired from a gun, gun powder residue on clothing determine distance NIBIN
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Crime Labs BCI structure
Latent Print section
finger prints AFIS pills finger prints
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Crime Labs BCI structure
Document Section
altered documents, forged checks, handwriting, printer , copies, and type writers, restoration of burnt of shredded documents
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Crime Labs BCI structure
Polygraph section
blood pressure , pulse, respiration, skin conductivity, tool of interagency
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Burglary
- trespassing in an occupied structure to steal something
- e.g a house
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Breaking and Entering
- trespassing in an unoccupied structure to steal something
- E.g a store
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Robbery
threaten or cause physical harm to someone while stealing something
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Theft
taking someones property without their knowledge
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warrant
written order from the court authorizing the search and seizure of
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Mimcey V. Arizona
- 1978 no homicide exception murder/crime scene exception
- scene must BE SECURED
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Crime Scene
the location where a crime took place and/or any location where a crime or subsequent investigation
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Primary Crime scene
where the actual offense took place
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Secondary Crime Scene
any location on separate from the primary scene that is related to the crime
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ARISN
1. Approach
2. Render Medical Aid
3. Identify suspect, additional victims, and witnesses
4. Separate the scene and physical evidence
5. make appropriate Notifications
Initial Response-ROle of first responder at a crime scene
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Arrive safely, asses the scene for danger, suspects biological natural and structural hazards.
maintain situational awareness
be observant for fleeing suspects or possible witnesses
be alert for possible evidence destruction
tire impressions, casting, blood
Approach
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saving lives is most important function of this point and takes priority over preserving evidence
but....attempt to do so without destroying possible evidence
request EMS if necessary and point out potential evidence to them
be aware of possible multiple victims
Render Medical Aid
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arrest and secure suspect keeping in mind possible evidence and clothing, shoe, hands, separate witnesses and obtain statements if suspect had fled issue BOLO (be on look out)
identify suspect, additional victims, and witnesses
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Secure the scene and physical evidence securing the scene (tape)
1. Secure the Perimeter- crime scene tape, cruisers. personnel, cones
consider multiple layers for media, non-essential personnel
make it large, it is easier to scale down later. remember point of entry and escape.
2. Crime Scene log- Running list of all who enter the scene, date, time in, time, out, purpose. Helps to prevent non-essential personnel from entering the scene
3. Securing physical evidence- protect fragile and transient evidence from weather and other conditions
secure scene and physical evidence
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supervisors
detectives
CS investigators
Cornor
additional personal for security
any specialized personnel
make appropriate notifications
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1. Initial Walkthrough
2. search for potential evidence
3. document the scene
4. collect and package evidence
5. complete additional processing
6. debrief
Steps @ Crime Scene
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Initial walkthrough
- obtain facts of the case
- discuss legal issues -search warrent
- determine size and scope of the scene
- determine size and scope of the scene
- determine what equipment or additional personnel may be needed
- reconfigure perimeter if needed
- set up equipment staging and use appropriate
- PPE - personal protection equipment
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searching the crime scene
- be thorough systematic and methodical
- consider the type of crime
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Objects were locate or foreign to the scene
objects that are in an unusual location
objects that have been damaged
when in doubt.... COLLECT IT
LOOK UP
Look for
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1. line/strip
2. grid
3. spiral
4. wheel/ ray
5. Quadrant Zone (usually bombing)
Five types of search patterns
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front=> back
exterior first, driver=> passanger=> trunk last
search pattern for cars
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Recording a Crime Scene
- Goal: permanently document the scene
- only have one chance to do it right
- assist the investigation (not and in the future) required for court
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1. notes
2. photographs
3. video
4. sketches
Recording the crime scene
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document everything, to write a report
detailed description of the scene and what was done
date, time, location, fact of the case , names
weather conditions and temp( inside, outside)
Condition of the scene (furniture overturned broken hems, forced entry open windows) descriptio of victims and wounds
location of evidence/movements of evidence
notes
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Photography goal
- goal accurately depict the scene as you found it (conditions, layout, evidence, spatial relationships line of sight
- complimentary to notes and sketches
- overshoot film is cheap and flash cards are cheaper
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Lenses
bends light to focus an image
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focal length
- distance between the lens and the image on the film/microchip
- 1. normal lens 50-55mm
- 2. telephoto lens 100 mm greater
- 3. wide angle lens <50mm
- 4. macro lens <50mm
- 5. multipurpose lens 28-80
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aperture
distance of the opening through which light enters the camera
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F-stop
a setting on the camera that controls the aperture diameter (F-number)
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