Standards DNA analysis and interpretation- Source level (001.1)

Version: 3.0

Date of approval: 12 December 2016

Date of effect: 12 December 2016

De datum van inwerkingtreding ligt voor de datum van uitgifte.

Part I. General Introduction to Standards

§ 1. Background to and aim of the Standards

Reporting forensic experts play a crucial role in the administration of justice. The NRGD aims to ensure justified confidence in forensic expertise for stakeholders. This confidence must be based on the demonstrable independently safeguarded quality of forensic investigators and their reports on the basis of (inter)national forensic-specific standards.

The NRGD is managed by the Board of Court Experts (hereinafter: Board). The Board’s core task is to rule on the applications for registration or repeat registration in the register of the NRGD (register). To that end the Board first defines the field of expertise. This is important in order to inform applicants, assessors and users of the register (e.g. judge, public prosecutor and attorney) about the activities an expert in the field of expertise in question engages in and about the activities that fall outside the field of expertise. The demarcation of the field of expertise is set out in Part II of these Standards.

The Board also determines the criteria on the basis of which an assessment is made for each field of expertise as to whether an application complies with the quality requirements. The generic requirements are set out in the Register of Court Experts in Criminal Cases Decree (Besluit register deskundige in strafzaken). These requirements are elaborated further for each field of expertise. This elaboration is set out in Part III of these Standards.

Furthermore the Board determines the assessment procedure. This procedure is described in Part IV of these Standards.

The NRGD has a system of periodic repeat registration. Court experts must demonstrate every five years that they still meet the requirements in force at that time. The Standards are dynamic and are being developed further in order to enhance the quality of the experts. These Standards set out the current state of the (sub-)field of expertise.

§ 2. Types of applicants

The NRGD distinguishes two types of applicants: the initial applicant and the repeat applicant. The initial applicant is a reporter who at the time of submission of the application is not yet registered in the register for the field of expertise to which the application relates. The repeat applicant is an expert who is already registered in the register for the field of expertise to which the application relates.

These two types of applicants are subdivided as follows:

Initial applicant:

Repeat applicant:

The initial applicant is an applicant who at the time of submission of the application does not have an NRGD registration. An initial applicant could be:

In respect of initial applicants, it is necessary to make a clear distinction between the independent reporter and the reporter without work of his own. An example of a reporter without work of his own is the newly-trained expert. This expert has completed the forensic training (reporter’s training), but has not yet been able to independently write the number of reports required for the assessment because these are written under the supervision of a tutor during the training. Another example of a reporter without work of his own is the reporter whose earlier application was rejected and who has been working (partly) under supervision following this rejection.

The Board adopts the following principle. Every applicant must draw up a List of Case Information. This list must include a specific number of cases in a period specified by the Board immediately preceding the application. If the List of Case Information includes one or more cases which have been prepared under supervision, the applicant will be qualified as a ‘reporter without work of his own’. An additional requirement applies to the applicant who was rejected earlier: the case reports included in the List of Case Information must have been drawn up after the date of the Board’s decision rejecting the earlier application (Policy Framework on Application after Rejection)1It is possible to make an exception to this general rule, namely in case of an earlier rejection pursuant to Article 12(2), sub-paragraph a, of the Register of Court Experts in Criminal Cases, the so-called training requirement. Reports written before the date of the Board’s decision rejecting the earlier application may be included in the List of Case Information, provided that they were drawn up within the generally applicable period preceding the time of submission of the new application.

The distinction between the various types of repeat applicants is important in the context of the assessment procedure: the documents a repeat applicant must submit, the composition of the Advisory Committee on Assessment and the assessment method.

§ 3. Justification of Standards

These Standards have been established by the Board in accordance with the Register of Court Experts in Criminal Cases Decree (Besluit register deskundige in strafzaken) and the Experts in Criminal Cases Act (Wet deskundige in strafzaken). Representatives from the various domains were consulted; users (judges, public prosecutors and lawyers) and subject matter experts in the field (professional organisations, representative associations, experts both at home and abroad). The draft of the Standards has also been published on the NRGD website for public consultation.

§ 4. Validity of Standards

The Standards are valid from the date shown on the cover. The validity runs until the moment of publication of a new version. In principle it will be checked annually as being up-to-date. This check can lead to a new version. The aim is to publish the new version no more than once a year.

§ 5. Version management and formal revision history

All changes made to the Standards lead to a new version. Newer versions of (parts of) the Standards are designated with a higher version number.

5.1. Version management

In the case of editorial changes the old version number is increased by 0.1. Editorial changes have no substantive impact. In the case of substantive changes the version number is increased by 1.

5.2. Formal revision history

The revision history starts with version 1.0 as the first formally approved version. Substantive changes made are briefly described in the revision history (Annex C). This makes it possible to trace which Standards are valid at any given moment at all times.

Part II. Demarcation of DNA – Source level

§ 1. Introduction

Within the field of DNA analysis and interpretation – Source level (hereinafter: DNA – Source level), the following questions are relevant:

§ 2. Core activities

Stated below is the description of the field of expertise DNA- Source level.

In a criminal law context, experts working in the field of DNA – Source level, primarily seek to answer question 2: From whom does the biological trace originate? In other words, who is the donor of the cellular material?

The DNA – Source level expert subjects the biological trace material to (Autosomal and/or Y-chromosomal) DNA analysis, and may subsequently perform DNA profile comparison. To do this, the expert compares DNA profiles from trace material with each other and/or with DNA profiles from reference samples.

In addition, comparisons may be made with DNA profiles in DNA databases.

The DNA – Source level expert is concerned with interpreting and comparing individual and complex and/or mixed DNA profiles obtained from the trace material under standard conditions or with the help of low template/minimal traces DNA techniques. The expert’s focus is on the whole scope of biological traces, including contact traces.

The tasks that fall within the field of DNA – Source level are:

Experts within the field of DNA – Source level are capable of applying Autosomal and Low Template/Minimal Traces DNA analysis techniques and are capable of interpreting, statistically evaluating and reporting on the results of these techniques.

Experts within the field of DNA – Source level are capable of applying DNA techniques used to answer question 1. ‘Are biological materials present on the exhibit and what is the nature of the cellular material in the biological trace?’even though not all DNA experts perform these analyses (anymore) themselves.

Experts within the field of DNA – Source level do not have to be able to answer question 3. ‘How was the biological material deposited?’. Being able to answer this question adequately is central to reporting at Activity level and requires specialised knowledge and expertise (See paragraph 2.2).

§ 3. Boundaries of the field of expertise

Within the practice of DNA – Source level, five specific types of questions exist that require additional expertise and experience, and therefore, fall outside the scope of DNA – Source level as registered by the NRGD:

When reporting as an expert registered for the field of DNA-Source level, the expert should be aware of the possibilities and limitations of the above mentioned techniques and/or specialisations, and in addition, the expert should be aware of the potential for international searches of intelligence databases and of new developments such as RNA, SNPs and Next Generation Sequencing. The expert should also be aware of the pros and cons of these techniques, specialisations and/or developments.

§ 4. Registration

The register will record the name of the relevant expert as an expert in the field of DNA- Source level.

Part III. Registration requirements for DNA analysis and interpretation – Source level

The general (repeat) registration requirements are given in the next paragraphs in italics with a reference to Article 12 paragraph 2 in the Register of Court Experts in Criminal Cases Decree (Besluit register deskundige in strafzaken).

An expert will only be registered as an expert in criminal cases upon submission of the application if, in the opinion of the Board, the expert:

§ 1. Article 12(2) sub-paragraph a

(...) has sufficient knowledge and experience in the field of expertise to which the application relates.

1.1. Initial: independent reporter

1.2. Initial: reporter without work of his own

1.3. Repeat applicant: after unconditional registration

1.4. Repeat applicant: after conditional registration

§ 2. Article 12(2) sub-paragraph b

(...) has sufficient knowledge of and experience in the field of law concerned, and is sufficiently familiar with the position and the role of the expert in this field.

§ 3. Article 12(2) sub-paragraph c

(...) is able to inform the commissioning party whether, and if so, to what extent the commissioning party’s question at issue is sufficiently clear and capable of investigation in order to be able to answer it on the basis of their specific expertise.

§ 4. Article 12(2) sub-paragraph d, e and f

An applicant is required to:

§ 5. Article 12(2) sub-paragraph g

(...) is able to give a verifiable and well-reasoned case report on the assignment and any other relevant aspects of their expertise in terms which are comprehensible to the commissioning party, both orally and in writing.

An applicant is required to:

§ 6. Article 12(2) sub-paragraph h

(...) is able to complete an assignment within the stipulated or agreed period.

§ 7. Article 12(2) sub-paragraph i

(...) is able to carry out the activities as an expert independently, impartially, conscientiously, competently, and in a trustworthy manner.

An applicant should:

§ 8. Hardship clause

The Board may decide not to apply or deviate from a registration requirement if application of such requirement would produce very unreasonable results. The hardship clause may only offer a solution in certain exceptional situations. It is up to the applicant himself to submit facts and circumstances showing that a certain registration requirement is unreasonable in his specific case.

Part IV. Assessment procedure for DNA – Source level

§ 1. General

In all fields of expertise the assessment will be based on the written information provided, including as a minimum requirement case reports and items of evidence, supplemented in principle with an oral assessment. However, such an oral assessment will not be necessary if the applicant's expertise has already been clearly demonstrated by the written information.

The assessment will in principle be carried out on the basis of the information provided by the applicant:

If it is felt necessary in the context of the assessment an additional case report and/or information, for example information about the way collegial review and/or supervision is organized within the organization, can be requested.

§ 2. Assessment procedure per type of applicant

2.1. Initial: independent reporter

1 It is left to the applicant to decide in which form this evidence is provided, e.g. in the form of a logbook or by means of certificates.

2.2. Initial: reporter without work of his own

1 It is left to the applicant to decide in which form this evidence is provided, e.g. in the form of a logbook or by means of certificates.

2.3. Repeat applicant: after unconditional registration

1 It is left to the applicant to decide in which form this evidence is provided, e.g. in the form of a logbook or by means of certificates.

2.4. Repeat applicant: after conditional registration

1 It is left to the applicant to decide in which form this evidence is provided, e.g. in the form of a logbook or by means of certificates.

Annex A. Summary of conceptsdna analysis and interpretation – source level

This document contains keywords for concepts of which an expert in the field of DNA- Source levelshould minimally have a basic knowledge.

Keywords

Forensic biology

Sources of DNA evidence

Crime scene investigation and laboratory analysis of biological evidence

Identification and presumptive testing of body fluids (blood, semen, saliva)

Confirmatory assays for body fluid identification (immunoassays)

Uncertainty concerning attribution of DNA (particularly at low levels) to specific body fluids

General

The structure of DNA and the variability of the human DNA genome

Loci, alleles, genotypes and DNA profiles

Polymorphisms commonly used for DNA testing

The molecular biological basis of forensic DNA tests; using the DNA profile to identify a forensic sample

Extraction and quantification of DNA

Polymerase chain reaction

Short tandem repeats and mutation processes

Forensic multiplex STR typing kits

DNA separation by CE and LIF detection

Analysis of results, including the use of ladders for fragment sizing, use of analytical thresholds and identification of artefacts such as stutter, ‘pull-up’ and identification of mixed samples.

QC/QA

Quality control and quality assurance of forensic DNA analysis

Laboratory accreditation, personnel certification and proficiency testing

Validation studies

Laboratory error rates

Understanding and minimizing the risk of contamination in the forensic process: methods of reducing the occurrence of contamination and detecting when it has occurred

Continuous improvement and quality

DNA statistics

Likelihood Ratio (LR)

Bayes Theorem

Product rule to calculate the probability of independent variables

DNA mixture deconvolution and recommended procedures for analysing mixed samples (LR and RMNE (‘Random Man not Excluded’)/CPI (‘Combined Probability of Inclusion’))

Accounting for relatives, where applicable, in calculating evidential strength

Database issues

Inclusion criteria and search (im)possibilities of the national DNA database including the detection of false negative and false positive matches.

Population Genetics

Hardy-Weinberg equilibrium/Linkage equilibrium

Population Substructure

Allele frequencies, genotype probabilities

Applying the product rule for independent events

Conditional match probabilities

Fst/Theta population substructure correction; correction for possible

allele dropout

Sampling variation in construction of DNA population databases

Proper Interpretation of the Evidence

Common Logical Fallacies (Prosecution/Defence Fallacy)

Evidential strength of database match

DNA database search controversy

Avoidance of cognitive bias

Minimal traces (Low Template DNA Analysis)

Evaluation of potential low template DNA typing results.

Allele and/or locus dropout due to degradation, preferential amplification, stochastic effects and stochastic thresholds.

Replication and consensus DNA profiles

Approaches for the statistical evaluation of DNA profiles from low template DNA samples

Y-chromosome Testing

Y-chromosome evolution and its consequences for forensic analyses

Patrilineal inheritance

Laboratory analysis of Y-chromosome STR’s

Population genetics of Y-STR haplotypes

Use of Y-STR population databases (YHRD)

Statistical evaluation of Y-chromosome haplotypes

Interpretation of Y-STR mixtures

Kinship DNA Testing

Inheritance of genetic polymorphisms

Technical procedures for determining kinship