Week 2 - Investigation Practice

Investigative Practice

‘Information work’ where the collection and interpretation of material equips you to draw inferences and develop a hypothesis.

Investigative material

Statements, Documents, reports, images, videos, recordings, physical exhibits

Physical exhibits

Weapons, clothing, stolen goods, biological samples, chemical material

Material Attrition

The categorisation of collected material as irrelevant/relevant; inculpatory or exculpatory evidence.

Investigative Actions

Actions taken during investigations including interviewing, role playing, scientific analysis, pattern analysis, and monitoring.

Criminal Investigation

The process of identifying a party guilty of committing a crime via the collecting and analysis of evidence.

Investigative Cycle

A series of steps including planning, understanding sources, examination, recording, and evaluation in the investigative process.

Investigation Plan structure

1. Intro 2. Scope and purpose 3. Resources and timeframe 4. List of affected people 5. Activities table 6. Risk management 7. Information register

Investigative thinking/ reasoning

The identification of possible theories or hypothesis, and the search for evidence that will support or eliminate those theories

Exculpatory Evidence

Evidence that exonerates or tends to exonerate the defendant of guilt.

Deduction

The process of reasoning from general propositions to specific conclusions.

Deductive Reasoning

Using existing information (propositions) to make neutral conclusions via inference

Induction

The process of moving from observations to general principles about cause-and-effect.

Abduction

Theory generation; identifying plausible theories of a case through creative processes.

Retroduction

The process of moving from observed effects to identify a cause.

Hypothesis Testing

A method of decision-making to determine whether data supports a particular explanation.

Investigative Decision-Making

Decisions about the collection, interpretation, and use of evidence during an investigation.

Logical Validity

An argument is valid if the conclusion follows from the premises according to the rules of inference.

Soundness

An argument is sound if the premises are factually true.

Rules of Inference

Laws of thought that govern the logical movement from propositions to conclusions.

Inductive Reasoning

The process of inferring conclusions on the basis of evidence, requiring observations about the world

Analogical reasoning

A form of inductions if two entities are alike in one respect, then they are alike in other respects

Casual Reasoning

Some effect is inferred from what is assumed to be the cause, vis versa

Causal Inference 1. Method of agreement

A pattern of inductive reasoning following that if two or more instances share a common singular circumstance, that circumstance is the effect/ cause of the instance

Causal Inference 2. Method of difference

If two or more cases of one phenomenon occur share only one common difference between when the phenomonenon does not occur, that circumstance is inferred to be causality connected to the phenomenon

Causal Inference - joint method of agreement and difference

The combination of methods of agreement and methods of disagreement used in combination to result in a higher degree of probability

Causal Inference - Methods of Residue

When certain effects are corresponded to known causes, the leftover effects are attributed to remaining antecedents

Causal Inference - Methods of concomitant variation

Concluded that when one phenomenon varies consistently with some other phenomenon , there is some causal relationship between the two

Decision errors type 1

Rejecting a null hypothesis when it is true

Decision errors

Failing to reject a null hypothesis when it is false

Abductive reasoning

Inferring a conclusion based on the theory that best explains a state of events (case theory)

Reproductive Reasoning

Inferring a likely cause based on the observation of effects: can include testing causes

Persuasive Inferences

Conclusions drawn via Abductive reasoning that are most likely

Persuasive causes

Identifying causal inferences that are most likely based in the observed effects

Legal significants

Factual theory matching elements of criminal offence: foundation in law, aligned offence elements, relevant material facts, access to legal clarification of uncertainties

Principle of investigation reasoning

1. Legal significants

2. Comprehensiveness

3. Plausibility

4. Parsimony

5. Minimalism

6. Consistency

7. Clarity

Comprehensive

A factual theory that accounts for all relevant evidence in a case

Plausibility

A factual theory linked o common sense understandings of how world/ humans operate

Parsimony

The simpler an explanation is the more likely it is to be true

Minimalism

A factual theory should address only those things relevant to prove elements of offence (complication can lead to reasonable doubt)

Consistency

Do not offer competing explanations (legal, not initial)

Clarity

A theory should be able to be explained within a few sentences, despite complexity

Argumentation

Forming reasons and drawing conclusions in application to a case (to convince trier of facts)

Informal Logic

Instrumental use of principles of inference, evidence, justification