24 terms

Forensic Science Chapter 2 Bertino- Hug

Terms for Chapter 2
chain of custody
the documented and unbroken transfer of evidence that follows exact procedures of logging and packaging evidence from crime scene to court.
circumstantial evidence
(indirect evidence) evidence used to imply a fact but not prove it directly. Example: hair, fibers, blood found at the crime scene
class evidence
evidence that narrows an identity to a group of persons or things
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 it commission based on evidence collected and witness testimony
direct evidence
evidence that (if true) proves an alleged fact, such as an eyewitness account of a crime or a video
individual evidence
a kind of evidence that identifies a specific person or thing. Examples are DNA, fingerprints, and bite patterns.
first responder
usually the first police officer to arrive at a crime scene
paper bindle
a folded paper used to hold trace evidence usually for internal packaging of small objects
secondary crime scene
a location other than the primary crime scene, but that is in some way related to the crime, where evidence is found
primary crime scene
the location where the crime took place
trace evidence
small but measurable amounts of physical or biological material found at a crime scene. Examples are hair, bullet casings, fingerprints.
crime scene sketch
A rough sketch is converted to a final sketch. The final sketch has a scale, lines are made using a ruler or computer program, north is labeled, two immovable landmarks (like walls) are shown, and other objects like furniture are drawn. Evidence is placed with symbols and a corresponding key. The drawing has a date, time, location, case number, and the names of the sketch artist and case supervisor.
search patterns
search patterns are determined by the size of the scene , the environment, and the number of personnel available to search. A group of searchers might use linear, zone and quadrant where a single person might use a grid, linear and spiral.
7 S's of Crime Scene Investigation
Secure the scene (control entry and exit to the scene), separate the witnesses, scan the scene (determine primary and secondary scenes), see the scene (photograph), sketch the scene, search for evidence and secure and collect evidence.
photographing the crime scene
Take 3 pictures, minimum of each piece of evidence, an overview, mid range, and closeup. Pictures should be taken at 90 degree angles to prevent distortion.
physical evidence
Evidence refers to any material items, marks or imprints that would be present at the crime scene, on the victims, or found in a suspect's possession that are not biological. Examples include tire prints, glass, paint, fibers etc.
breaking a scene into 4 equal sections and specifying them by direction. Example: NW quadrant.
packaging evidence
liquid and arson remains must be secured in airtight unbreakable containers and biological evidence must be dried before packaging. Sharps and Weapons need special internal packaging.
biological evidence
Examples: Blood, semen, saliva, sweat, tears, hair, bone, tissues, urine, feces, animal material, insects, bacteria, fungi, botanical matter. Evidence with living or previously living cells.
secret or illegal cooperation or conspiracy, especially in order to cheat or deceive others. Example: witnesses are not separated and they agree to make up a story about what happened or what they saw at a crime scene.
Locard's exchange principal
Every contact leaves a trace; when a person comes into contact with another person or object there is a cross transfer of physical evidence
staged crime scene
a crime scene where the evidence does not match the testimony of the witness. Initially all deaths should be investigated as homicides.
chemical evidence
a type of physical evidence that is made of a non biological substance like powders, paints, drugs, cleaning fluids,cosmetics, and gunshot residue