Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Advanced Forensic Science > Topic 2 - Case, Assessment & Interpretation > Flashcards

Topic 2 - Case, Assessment & Interpretation Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

What does the Court Justice System expect of the Police & Courts?

A
  • Intelligence – timely information to link or exclude suspect (DNA, fingerprints, mobile phones, CCTV) etc
  • Corroborative evidence – to support charge/prosecution (all forensic potential discovered in casework)
  • Timely scientific support through all stages of Criminal Justice System
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

rapid, quality, clear, good, partnership, objective

What does the Court Justice System expect of Politicians & Society?

A
  • Rapid DNA results, quality assured casework, clear statements, good testimony
  • An impact on crime, crime reduction & crime prevention
  • Partnership projects in serious & volume crime
  • An objective measure of ‘value’
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

1990

Where did CAI originate?

A
  • Forensic Science Service became an Executive Agency of Home Office
  • Direct charging of police for forensic services
  • Development of forensic products (samples and other evidence)
  • Costs were no longer invisible to the police
  • In the early days there was a charge per item you wanted to examine
  • Due to these extra costs there was a lot of attempts to cut corners and not submit certain evidential items leading to wrong conclusions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

1999

Why did the CAI originate?

Experiencing a range of issues

A

The Forensic Science Service was experiencing a range of issues:
- Experiencing significant case backlogs & long turnaround times
- Constantly re-negotiating delivery dates
- Drowning in unnecessary examinations & lengthy (manual) analytical processes
- Struggling even to meet some court dates
- Failing to meet the needs of police & CJS clients

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What year did the forensic database go live?

A

1995

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What did the 1988 Govt Act introduce?

A
  • There was a requirement for ‘Best Value’ although they tended to opt for the lowest cost
  • Police Authorities were not exempt
  • The forensic costs were no longer inivisible
  • They did a cost review for better resource allocation & best value
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What were the objectives of the CAI model?

CJS, relationships

A
  • Improve decision making and resource allocation
  • Improve relationships and develop partnerships
  • Provide value (defined by client agency)
  • Service the needs of the Criminal Justice System
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the assessment in CAI?

A

How we manage, priotise and triage the demand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How many stages does the CAI model have?

A

3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the first stage of the CAI model?

A
  • Customer requirement
  • Case Information
  • Customer Needs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does the second phase of the CAI model involve?

A
  • Case pre-assessment
  • Determine forensic strategy
  • Identify propositions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What does the third phase of the CAI model involve?

A
  • Service delivery
  • Forensic examination
  • Evaluate outcomes
  • Interpretation & Report
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What should you identify first in a case?

A

The defence and prosecution propositions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q
A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Determine the propositon level

Has the semen originated from the suspect?

A

Source level

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Determine the propositon level

Has the suspect had sexual intercourse with the complainant?

A

Activity level

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Determine the propositon level

Did the suspect rape the complainant?

A

Offence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What level is source level propositions?

A
  • Level 1
  • They require the least amount of information and expertise
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What level is activity level propositions?

A
  • Level 2
  • Requires more expertise and information than source level but less than offence level
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What level is offence level propositions?

A
  • Level 3
  • This requires the most expertise and information
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Determine the propositon level

The blood on Mr C’s clothing came from Mr Z

A

Source level proposition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Determine the propositon level

The glass fragments came from window X

A

Source level

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Determine the propositon level

The blood on Mr C’s clothing came from an unknown person

A

Source level proposition supporting the defense

24
Q

Determine the propositon level

Mr A committed the burglary

A

Offence level

25
Q

Determine the propositon level

Mr A was not present when the window was smashed

A

Activity level

26
Q

Determine the propositon level

The DNA profile matches Mr B

A

Source level

27
Q

Determine the propositon level

Mr C assaulted Mr X

A

Offence level

28
Q

Determine the propositon level

The DNA profile on the swab does not match Mr A

A

Source level

29
Q

Determine the propositon level

Mr B had sexual intercourse with Ms Y

A

Activity level

30
Q

requirements, examination, decision, value

What does the CAI provide for investigators?

A
  • Ensures requirements are clearly articulated
  • Assists in setting forensic examination strategy
  • Assists decision making
  • Enhances Value (cost/time vs. usefulness = value)
31
Q

Ensures a…

What does the CAI model provide for the CJS?

Discussion

A
  • Ensures a balanced (unbiased) approach
  • Ensures impartiality and transparency
  • Allows discussion of strength of evidence
  • Adds value (not to be confused with cost)
32
Q

What is the upside down triangle for the forensic process

A
  1. Crime Scene examination (investigation)
  2. Laboratory examintion (evaluation)
  3. Court Adjudication
33
Q

What is the posterior odds equation for the court?

A

Pr(G|E) / Pr(Ḡ|E)

34
Q

What is the likelihood ratio equation for the scientist?

A

Pr(E|G) / Pr(E|Ḡ)

35
Q

Prior odds equation

A

Pr(G) / Pr (Ḡ)

36
Q

How can you calculate the posterior odds?

A

Likelihood ratio X Prior odds

37
Q

What do the terms stand for in the prior odds equation?

A

E = evidence
G = Guilty
Ḡ = Innocent
Pr = Probability of

38
Q

case, examination, propositions, reporting, theory, role

What does the CAI model provide for forensic scientists?

A
  • Ensures clear understanding of case information and issues
  • Leads to an agreed forensic examination strategy
  • Defines propositions for testing
  • Ensures staged examination and reporting is underpinned by sound statistical theory
  • Adds value to the scientist’s role
39
Q

What is the I / Information in Bayes Theorem?

A

Evaluation must be carried out within a framework of circumstances

40
Q

What is conditioning information in Bayes Theorem?

A
  • Conditioning information refers to the additional knowledge or data that is used to update the probability or hypothesis of an event.
  • When determining the LR or other probabilities the scientist must make clear their understanding of the case circumstances relevant to their evaluation.
41
Q

What must the scientist consider their observations in light of in Bayes Theorem?

A

The scientist must consider their observations in the light of prosecution Hp and defence Hd propositions

42
Q

What must clearly be stated in Bayes Theorem?

A

The propositions must be clearly stated and are subject to change

43
Q

What must the scientist consider in terms of probability in Bayes Theorem?

A

The scientist must consider the probability of their findings E if the prosecution proposition were true and if the defence proposition were true

44
Q

What does the relationship of the two probabilities in Bayes Theorem determine?

A

The relative magnitude of these two probabilities (The Likelihood Ratio [L]) - determines the assistance provided by their findings in weighing the two propositions against each other.

45
Q

What does the logic principle of Bayes Theorem require you to address?

A

Address the probability of the evidence E given the proposition H and the background information I

46
Q

What is transposing the conditional?

A

The probability of the proposition given the evidence

47
Q

What does the balance principle of Bayes Theorem require you to address?

Address

A
  • Address at least one pair of propositions one based on the prosecution issue Hp and one based on an alternative or defence issue Hd
  • If a reasonable alternative cannot be identified, the expert may address only the one proposition, but making it clear they cannot evaluate the strength of the evidence
48
Q

What is the likelihood ratio equation?

A

Probability (Pr) of the Evidence (E) given The Prosecution hypothesis (Hp) and the information (I) divided by the Defence hypothesis (Hd) and the information (I)

49
Q

What is a partial defence?

A

Where the defence will say it didn’t happen the way it was posed, they will admit to part of it but not all of it

50
Q

Lab

Where are the figures for the likelihood ratio obtained?

A

They are a combination of the scientists experience in the case they’re working with and the lab management system

51
Q

What does an LR value > 1 support?

A

It supports the prosecution hypothesis (Hp)

52
Q

What does a LR value <1 support?

A

The defense hypothesis (Hd)

53
Q

What does an LR value close to or equaling 1 support?

A

It doesn’t support the defense nor the hypothesis proposition and provides weak evidence for both

54
Q

what does an LR value of 1000 support?

A

It provides strong evidence the supports the prosecution

55
Q

What does an LR value of 0.001 support?

A

It provides strong evidence to support the defence.

56
Q

Part 1

What are the key standards for an expert opinion?

A
  • Establishing the key issue in the case
  • Consider available, relevant information and, where necessary, request additional information
  • Discuss with the relevant customer
  • Identify relevant propositions
  • Pre-assessment
  • Identify potential outcomes
  • Assign estimated probabilities
  • Estimate Likelihood Ratios
  • Commissions examinations to best progress the issue in the case
57
Q

Part 2

What are the key standards for an expert opinion?

A
  • Documentation (clearly on the case file)
  • The key issue and propositions addressed
  • Sources of data used in assigning probabilities
  • Examination strategies
  • Reports and statements
  • Conditioning information
  • Items received and examined
  • Significant findings and conclusions
  • Strength of evidence expressed as LR or verbal scale related to LR
  • Disclosure paragraph

Advanced Forensic Science (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions