Prosecution Hypothesis (Hp)
Definition
The proposition advanced by the prosecution, typically that the defendant is the source of the recovered material or was present at the scene. Paired with the defence hypothesis to define the comparison for the likelihood ratio.
- Also called
- Hp
- Typical content
- Defendant is source of trace or was present at scene
- Position in LR
- Numerator
- Paired with
- Defence hypothesis (Hd)
Common questions
Does a high likelihood ratio prove the prosecution hypothesis is true?+
No. A high LR means the evidence is far more probable under Hp than Hd, but the final probability of Hp being true also depends on the prior odds before the evidence, which the court, not the scientist, is responsible for weighing.
Who formulates the prosecution hypothesis in a given case?+
It usually reflects the specific allegation the prosecuting party is making, communicated to the forensic scientist through case instructions, and the scientist evaluates the evidence against that stated hypothesis rather than inventing it independently.
Related terms
- Defence Hypothesis (Hd)
- The proposition advanced by the defence, typically that the material came from an unknown unrelated individual or that the defendant was not...
- 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...
- Posterior Odds
- The ratio of the probability of the prosecution hypothesis to the probability of the defence hypothesis after the forensic evidence is taken...
- Prior Odds
- The ratio of the probability of the prosecution hypothesis to the probability of the defence hypothesis before the forensic evidence in question...
- 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...