Offence-Level Proposition
Definition
A proposition about guilt. Example: 'The suspect committed the assault' versus 'The suspect did not commit the assault.' Forensic scientists must not evaluate evidence at the offence level because doing so requires the scientist to weigh all case evidence, a task reserved for the jury or court.
- Hierarchy level
- Highest, above activity and source level
- Reserved for
- Jury or court, not the forensic scientist
- Example pair
- "Suspect committed the assault" vs did not
Common questions
Why can't a forensic scientist evaluate evidence at the offence level?+
Weighing guilt requires considering all the evidence in a case, including testimony and material the scientist has no access to or competence to assess, so doing so would overstep the scientist's role and usurp the fact-finder's function.
How does this differ from the activity-level proposition scientists do address?+
Activity-level propositions ask whether the evidence supports a specific act, such as contact or presence at a scene, which the scientist can evaluate against the forensic findings without pronouncing on overall guilt.
Related terms
- Activity-Level Proposition
- A proposition about what happened. Example: 'The suspect handled the knife' versus 'The suspect never handled the knife.' Activity-level propositions require the...
- Likelihood Ratio (LR)
- The ratio of two conditional probabilities: the probability of the observed evidence given the prosecution's hypothesis (same source), divided by the probability...
- Prosecutor's Fallacy
- The error of treating the RMP (or its reciprocal) as the probability that the defendant is innocent, or as the probability that...
- Source-Level Proposition
- A proposition about the origin of material. Example: 'The DNA profile originated from the suspect' versus 'The DNA profile originated from an...
- Verbal Equivalent Scale
- A standardised mapping from LR ranges to descriptive phrases, such as the ENFSI scale: LR 10 to 100 corresponds to 'moderate support',...