ENFSI Evaluative Reporting Framework
Definition
The ENFSI Guideline for Evaluative Reporting in Forensic Science (2015), which specifies that forensic identification opinions should be expressed as likelihood ratios or on a verbal scale from very strong support to weak support. Adopted by UK FSR, Dutch NFI, Swedish NFC, and other ENFSI member laboratories.
- Document
- ENFSI Guideline for Evaluative Reporting in Forensic Science
- Year
- 2015
- Reporting format
- Likelihood ratio or a verbal scale, very strong to weak support
- Adopting bodies
- UK FSR, Dutch NFI, Swedish NFC, other ENFSI members
Common questions
Why express findings as support for a hypothesis rather than a probability of guilt?+
The framework restricts the examiner to weighing the evidence under two competing propositions, which keeps the expert within their forensic-science competence and leaves the ultimate question of guilt, which combines all trial evidence, to the court.
What happens when a laboratory cannot calculate a numerical likelihood ratio?+
The framework allows a verbal-scale opinion anchored to qualitative reasoning about the same two-hypothesis structure, used when the underlying data for a numerical LR is not available, though it is considered a weaker basis than a validated statistical model.
Related terms
- 2009 NAS Report
- The National Academy of Sciences report Strengthening Forensic Science in the United States, which found that fingerprint individualization claims lacked empirical population-frequency...
- Categorical Identification
- The historical fingerprint testimony model in which the examiner declares that the latent print originated from the named person to the exclusion...
- FRStat
- The fingerprint statistical scoring model developed by the FBI Laboratory and Iowa State University (Professor Alicia Carriquiry). Takes ACE-V comparison documentation as...
- 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...
- NIST ELFT-EFS (2012)
- The NIST Evaluation of Latent Fingerprint Technologies: Extended Feature Sets, a large-scale evaluation of both automated AFIS algorithms and human examiner performance....
- Population Frequency Database
- The reference dataset from which the denominator of a fingerprint likelihood ratio is estimated: the frequency with which a given configuration of...
- R V. T (2010)
- UK Court of Appeal decision on footwear evidence likelihood ratios that expressed caution about numerical LR presentation where the underlying database was...
- Ulery Et Al. 2011
- The FBI black-box study that tested 169 fingerprint examiners on 744 latent-exemplar pairs, finding a false-positive rate of 0.1%. The study empirically...
- Verbal Scale
- The ENFSI translation of numerical likelihood ratios into courtroom language: very strong support (LR over 10,000), strong support (LR 1,000-10,000), moderate support...