lecture 2 - evidence Flashcards
forensic science plays important role in criminal law
- supplies vital information about how a crime was committed and who committed
- if it is not court approved,,, it is not evidence
how are the rules of evidence used to determine whether something is in/admissible
- serve to screen out, or exclude, irrelevant or prohibited evidence
rules of evidence are applied to determine the admissibility of all information:
- eyewitness testimony
- photographs
- physical objects
- scientifically generated information like DNA
forensic evidence is the _ _ _ _
scientific generation of facts
forensic evidence has a distinct set of procedures
- good science
- relevant
- correctly collected
- thoroughly documented
evidence is used to __ the __ of crime
reconstruct, events.
admissibility of evidence
- solid supportive foundation for any offer of evidence
- enough evidence to convince a judge that the proposed item of evidence is true
admissibility hearings must be:
- reliable
- relevant to the case at hand
- for scientific analysis - court must be assured that the methods used are scientifically acceptable and reliable
- falsifiable
admissibility hearings provide __
- a way for new scientific methods to be introduced and accepted as viable tools in forensic science
Frye Decision - 1920
- charged with second-degree murder of physician named Robert Brown
- defence attempted to get an expert to testify that Frye had taken and passed lie detector test
- judge said no as they rejected scientific validity of lie detector due to new technology
- Frye was convicted, he appealed, decision was upheld
Frye Standard
- established criteria known as general acceptance (is it real or valuable)
- court must decide whether questioned procedure/technique/principle is “generally accepted” by a meaningful segment of the relevant scientific community
federal rules of evidence - rule 702
- you can give an expert opinion if you can prove yourself to be an expert
- however, did not specify who a witness was to be qualified and what specifically the court should weigh in making that assessment
Daubert Decision 1993
- v. Merrell Dow Pharmaceuticals
- Jason Daubert and Eric Sheller born with serious birth defects
- believed Benedictin, morning sickness med, caused it
- both sides submitted evidence that reached different conclusions
- Supreme Court ruled that general acceptance is not absolute requirement for determining admissibility
- established role of a trial judge as gatekeeper
5 factors of Daubert criteria court may consider
- has the technique been tested in actual field conditions
- has technique been subject to peer review and publication
- what is known or potential rate of error
- do standards exist for the control of the technique’s operation
- has the technique been generally accepted within the relevant scientific community
3 decision which significantly impacted the way evidence admissibility is addressed
1) Daubert -> judge as gatekeeper
2) Joiner -> court rejected animal studies because they focused on different chemicals at different exposure levels (did not pass daubert criteria and relevant test)
3) Kumho Tire -> Kumho extended Daubert ruling to all expert (i.e. mechanic) and not just traditional scientific experts
inclusive vs exclusive evidence
- inclusive is evidence included in the population of items that could have been the source of the evidence in question
- exclusive is evidence is excluded from the population of items that could have been the source of the evidence in question
direct vs circumstantial evidence
- direct is that which is known to a person by personal knowledge, such as eyewitness testimony
- circumstantial is evidence that requires inference to move logically from the information provided to the answer to a question -> evidence must still be tied to subject
reconstruction of evidence
- provides information about the events preceding, occurring, during and occurring after commission of a crime
- involves logic, observation, experience and evaluation of witness statements
associative evidence
- associate or dissociate a suspect to a crime
exemplar
- sample of known origin used as a reference
class characteristics **!!
- does not reference a particular suspect
- has ability to narrow a field down to a group
- example blood type or height
individual characteristic **!!
- evidence does associate a particular individual with the commission of a crime
- has ability to pinpoint a source
- example DNA or fingerprints
ultimate goal of forensic science:
- link potential offender to a crime scene
- individual evidence is ideal, but class evidence still extremely important
significance of evidence depends on 4 factors:
- location evidence was collected
- type of evidence
- quantity of evidence
- condition of evidence
