SIST EN ISO 21043-4:2025

Science criminalistique - Part 4: Interpretation (ISO 21043-4:2025)

This document specifies requirements and provides recommendations for the interpretation of observations to reach opinions that answer questions that are relevant for decision making in investigations or legal proceedings. This document states requirements that are applicable to all forensic disciplines. This document states requirements that apply when the opinion is based directly on human judgement and when the opinion is based on interpretation through a statistical model. This document is applicable to interpretation that occurs at a scene, within a facility, or within a judicial setting.
This document establishes requirements designed to safeguard the process for the interpretation of observations including the use of either statistical models or human judgement, to address alternative propositions based on the questions asked by the customer.
Interpretation is not necessary and the requirements of this document do not apply if the observations resulting from the analysis directly answer the relevant question.
EXAMPLE            In analytical chemistry, substances are often identified or classified. Provided that the applied analytical methods are not limited in selectivity or sensitivity for the given question, the observations can lead to a direct statement of the name of the substance (identification) or a type of material (classification). This is not considered interpretation for the purposes of this document.

Forensik - Teil 4: Interpretation (ISO 21043-4:2025)

Science criminalistique - Partie 4: Interprétation (ISO 21043-4:2025)

Le présent document spécifie des exigences et fournit des recommandations pour l’interprétation d’observations afin d’obtenir des avis qui répondent à des questions pertinentes pour la prise de décision dans le cadre d’enquêtes ou de procédures judiciaires. Le présent document énonce des exigences applicables à toutes les disciplines criminalistiques. Il énonce les exigences qui s’appliquent lorsque l’avis est basé directement sur un jugement humain et lorsque l’avis est basé sur une interprétation selon un modèle statistique. Le présent document s’applique à l’interprétation effectuée sur une scène (d’incident), dans des installations ou dans un cadre judiciaire.
Il établit des exigences destinées à protéger le processus d’interprétation des observations, y compris l’utilisation de modèles statistiques ou du jugement humain, ou les deux, pour traiter des propositions alternatives basées sur les questions posées par le client.
Aucune interprétation n’est nécessaire et les exigences du présent document ne s’appliquent pas, si les observations résultant de l’analyse répondent directement à la question.
EXEMPLE             En chimie analytique, des substances sont souvent identifiées ou classées. À condition que les méthodes d’analyse appliquées ne soient pas limitées en matière de sélectivité ou de sensibilité pour la question donnée, les observations peuvent conduire à une déclaration directe du nom de la substance (identification) ou d’un type de matériau (classification). Cela n’est pas considéré comme une interprétation aux fins du présent document.

Forenzične znanosti - 4. del: Razlaga (ISO 21043-4:2025)

General Information

• Status: Published
• Public Enquiry End Date: 29-Jun-2024
• Publication Date: 24-Sep-2025
• ICS: 07.140 - Forensic science
• Technical Committee: I13 - Imaginarni 13
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 27-Jun-2025
• Due Date: 01-Sep-2025
• Completion Date: 25-Sep-2025
• Ref Project: EN ISO 21043-4:2025 - Forensic sciences - Part 4: Interpretation (ISO 21043-4:2025)

Standards Content (Sample)

SLOVENSKI STANDARD
01-oktober-2025
Forenzične znanosti - 4. del: Razlaga (ISO 21043-4:2025)
Science criminalistique - Part 4: Interpretation (ISO 21043-4:2025)
Forensik - Teil 4: Interpretation (ISO 21043-4:2025)
Science criminalistique - Partie 4: Interprétation (ISO 21043-4:2025)
Ta slovenski standard je istoveten z: EN ISO 21043-4:2025
ICS:
07.140 Forenzika Forensic science
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 21043-4
EUROPEAN STANDARD
NORME EUROPÉENNE
June 2025
EUROPÄISCHE NORM
ICS 07.140
English Version
Forensic sciences - Part 4: Interpretation (ISO 21043-
4:2025)
Criminalistique - Partie 4: Interprétation (ISO 21043- Forensik - Teil 4: Interpretation (ISO 21043-4:2025)
4:2025)
This European Standard was approved by CEN on 26 August 2024.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 21043-4:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 21043-4:2025) has been prepared by Technical Committee ISO/TC 272
"Forensic sciences" in collaboration with Technical Committee CEN/TC 419 “Forensic Science
Processes” the secretariat of which is held by NEN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by December 2025, and conflicting national standards
shall be withdrawn at the latest by December 2025.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 21043-4:2025 has been approved by CEN as EN ISO 21043-4:2025 without any
modification.
International
Standard
ISO 21043-4
First edition
Forensic sciences —
2025-06
Part 4:
Interpretation
Criminalistique —
Partie 4: Interprétation
Reference number
ISO 21043-4:2025(en) © ISO 2025

ISO 21043-4:2025(en)
© ISO 2025
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
ISO 21043-4:2025(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 General requirements . 1
5 Questions and propositions . 2
5.1 Questions .2
5.1.1 General .2
5.1.2 Types of questions.2
5.1.3 Classification, including identification .2
5.1.4 Quantification .2
5.1.5 Question of source .3
5.1.6 Reconstruction . . .3
5.2 Addressing the question with either investigative or evaluative interpretation .4
5.2.1 General .4
5.2.2 Investigative interpretation .4
5.2.3 Evaluative interpretation .4
6 Types of opinions . 4
6.1 General .4
6.2 Likelihood ratios .5
6.3 Categorical opinions .5
6.4 Explanations .5
6.5 Estimations .5
7 Assigning probabilities . 6
7.1 General .6
7.2 Statistical-model-based assignment of probabilities .6
7.3 Human-based assignment of probabilities .6
8 Expression of the opinion . 6
8.1 General .6
8.2 Quantitative expression of opinion .6
8.3 Qualitative expression of opinion .7
8.4 Categorical opinions .7
Annex A (informative) Likelihood ratio . 8
Annex B (informative) Examples of opinion scales . 9
Annex C (informative) Examples of interpretation .11
Bibliography . 14

iii
ISO 21043-4:2025(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this do
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