Quality assurance of forensic experts needs expanding

Michel Smithuis*, Expertise en Recht, Edition 1 (2023) 

Much has changed in the area of forensics since the founding of the Netherlands Register of Court Experts (hereinafter: NRGD) in 2010. The register's introduction constituted an improvement to the safeguarding of the quality of expert contributions in the justice system.

NRGD's 12.5-year existence in perspective

History of the NRGD

In response to a miscarriage of justice such as in the Schiedam Park Murder, in which the expert opinion was under discussion, an investigation was conducted by advocate general Posthumus. His report included numerous recommendations for the entire criminal justice system, with the aim of helping to prevent the occurrence of such errors. In 2009, the Experts in Criminal Cases Act was passed and, with it, the NRGD was established. What public function has the NRGD been given? What is the status of the NRGD now, but also of the field, after 12.5 years?

NRGD's function

The NRGD was established by law in 2010 in order to safeguard the quality of experts in the criminal justice system.1 It follows from the Experts in Criminal Cases Act that is aimed at promoting the use of experts in criminal cases who, in the opinion of the independent Board of Court Experts (hereinafter: the Board), meet the quality requirements prescribed by law. This is done by bringing together the details of these experts and making them publicly available in the register.2

The Board administers the NRGD as an organisation and manages the register. For each area of expertise, the Board determines the specific requirements that must be met by  experts in order to be included in the register. It determines the assessment method as well. The Register of Court Experts in Criminal Cases Decree also stipulates that the Board is charged with adopting a code of conduct that sets out the rules of conduct, to which registered experts are required to adhere.3

Over the years, the NRGD4 has grown to become the leading forensic quality assurance organisation for the justice system in the Netherlands. Collaboration in the Netherlands and abroad are of paramount importance in this regard. The NRGD ensures that forensic analysts and their reports satisfy national and international standards. As a result, stakeholders can be confident of the quality of forensic expert examinations. As an independent and transparent organisation, the NRGD promotes and guarantees the quality of the forensic expertise. It also fosters the development of the quality of the field of forensics as a whole. The NRGD focuses on regulation, advice and knowledge exchange.

A look back at the period from 2010 to the present day

Whilst determining the working method in 2010, it was found that there were virtually no professional associations that had forensic quality requirements. Nor did any universities offer degree programmes to train to be a forensic expert. It was mostly something you became through hands-on experience.

In the initial phase (2010-2015), the NRGD's activities therefore consisted mostly of drafting quality requirements, developing assessment procedures and building up the register. That was no easy task. Quality requirements had to be determined for each area of expertise. That was done in consultation with the professional field: Dutch and foreign experts, scholars and legal experts. In a sense it was about codifying the consensus on the profession. In practice, this proved a labour-intensive and time-consuming endeavour, due to the need to exercise due care. There are a great many specialised fields within the natural sciences, for which the same process had to be completed as with the more general ones.

The experts who worked in the area in question then had to be assessed based on the quality requirements before they could be entered into the register. The process of building up the register therefore took longer than initially expected.

Since then, quality requirements have been developed for twelve areas of expertise – many of which have multiple subcategories – including DNA, Forensic Pathology, Digital Forensics, and Forensic Psychiatry, Psychology and Orthopedagogy. New areas, such as Forensic Financial Investigation and Bloodstain Pattern Analysis are under development. New areas, such as Radiology, are also being explored. As of 2022, more than 650 experts were listed in the register.

The Research and Documentation Centre (WODC) periodically evaluates the implementation of the Experts in Criminal Cases Act and concluded in 2020 as follows:

'The evaluation shows that the NRGD has made an important contribution to the purpose of the Experts in Criminal Cases Act of increasing the trust in the judiciary by realising quality improvements and quality safeguards in forensic consultancy.'5

What makes the NRGD's working methods extraordinary is that a degree/training and continuing education points (PE-punten) are not the only requirements for registration. The expert's work, i.e. reports that they have been prepared over the last few years, is also assessed by a peer review committee. The NRGD does this with a committee consisting of colleagues and a legal expert.

The NRGD aims for quality assurance to take place as much as possible at the source. The point of departure that the quality of the work carried out by experts is adequately safeguarded through training and professional development and the associated assessments. Over time, the Netherlands Forensic Institute (NFI) and the Netherlands Institute of Forensic Psychiatry and Psychology (NIFP) have continued developing their existing in-house training programmes to include clear learning objectives, modules, monitoring and examinations. For the NRGD, this was a reason to formulate policy for training programme recognition, in addition to conducting the individual assessments. If a training programme is successfully completed, inclusion in the register may follow. This means that the system that exists in practice in which assessment is done twice (once at the body itself and once at the NRGD) can be eliminated. The NRGD has, however, embedded a few quality guarantees. For example, recognition can only be obtained following a prior site visit by an independent assessment committee and the assessment is carried out at the faculty offering the degree programme/training with an external examiner from the NRGD on the Examination Board. This external examiner has the power of veto.

In 2019, the NIFP was the first to obtain recognition, for the training programme to become a behavioural expert who draws up reports. For the time being, this recognition applies to the initial registration of recent graduates and not to the five-year re-registration. Recently, recognition was also obtained for the training programme to become an administrative and civil law medical specialist (NVMSR). The NRGD is in talks with similar organisations that train forensic experts, such as the NFI, the Netherlands School of Public and Occupational Health (forensic doctors) and the foundation advising courts in environmental law and spatial planning disputes (STAB).

Ad hoc experts

In accordance with the Register of Court Experts in Criminal Cases Decree, the NRGD standardises areas of expertise that are well defined and for which standardisation and assessment can be achieved in an objective manner. In the criminal justice system, experts are sometimes asked for whom a regular assessment is not possible. This can include, for example, experts who may be asked to draw up a report for a criminal case only once in their entire career because of their particular or specialist knowledge. These experts have little or no forensic training or experience, nor can their forensic competence be guaranteed prior to the investigation or reporting. The Minister of Justice and Security has asked the NRGD to develop quality assurance instruments in cooperation with the professional field that can be used for these so-called Ad hoc experts. With the assistance/advice of the police/National Expertise Broker (LDM), Public Prosecution Service (OM), the judiciary (ZM) and the NFI, the NRGD has developed several instruments that are suitable for judges, officers and lawyers, on the one hand and experts, on the other. These consist of reporting guidelines, a questionnaire for users to determine whether an expert possesses the necessary skills and a system for assessing clarity, consistency and usability of a report. A digital learning module has also been developed, which enables Ad hoc experts to prepare for their role as an expert in the criminal justice system and the requirements associated with that role based on the Code of Conduct.


In the interest of the judicial process, the NRGD tries to offer a wide range of experts. Whether that will succeed will, however, depend primarily on actually creating longer-term demand. Only if private providers are given sufficient cases, for a sufficient number of years, at an adequate price will a segment for second opinions be able to emerge. This initially led to only a slight increase in the use of private providers. In the last few years, DNA analysis has shifted more and more towards private providers. This trend is expected to continue. This not only applies to DNA analysis, but also other kinds of expertise, including toxicology and pathology. As a result, the playing field is expanding beyond the NFI. The same quality requirements must of course apply to this, too, meaning that the investigation must in principle also be conducted by experts registered with the NRGD.

Advice and knowledge exchange

Quality is about more than just registering qualified experts. Quality is the culmination of the efforts of all parties involved in each link of the forensic chain, from the investigation through to the trial. The NRGD increasingly shares knowledge with and provides advice, both when asked and on its own initiative, to the police, justice system, NFI and NIFP, as well as parliament  with regard to the safeguarding of the quality of forensic expertise. At international level, the NRGD contributes to the discussion on the quality of forensic investigations. The NRGD is involved more and more frequently in various discussions and consultations with regard to the quality and safeguarding of forensic expertise. Examples of this include the drafting of the Visie op forensisch onderzoek (Vision for forensic investigation), of the action plan for the European Forensic Science Area and of ISO standards for forensic investigation. The NRGD provided advice to the Autopsy Task Force.

Organisations and policymakers, who want to invest more in quality, do not always know how to go about it or what to invest in. The NRGD increasingly shares knowledge by means of publications, lectures, presentations as well as via its own website. By participating in training programmes, new experts can familiarise themselves with quality standards. For example, the NRGD takes part in the NIFP programme for beginning behavioural experts who draw up reports and provides the module for the supervisor training programme.

The NRGD wants to bring together register users (ZM/OM/members of the legal profession), policymakers and experts through the organisation – possibly jointly – of  quality sessions and 'professional encounters'. This type of knowledge transfer has produced positive results in recent years. For example, lunchtime sessions have been organised between cybercrime experts and judges in various courts. Another initiative involved bringing together behavioural experts, the NIFP and members of the legal profession to increase the enthusiasm for drawing up reports for the legal profession.

Issues and challenges

A single register for the entire justice system

It has always been the legislator's goal to eventually expand the NRGD to include administrative and civil law. After all, expertise plays a role in all areas of law. For example, in social security law or occupational disability law, in which the input of experts (medical specialists, insurance doctors) can play a decisive role. Experts from STAB are another example.

The justice system (e.g. judges) has repeatedly stated that it is in urgent need of statutory quality assurance measures, including the registration of experts who are responsible for drawing up reports in administrative and civil law cases. The justice system is once again submitting a request to the ministry to have the quality of experts who work in administrative and civil law safeguarded in a manner similar to those in criminal law. The NRGD welcomes this request.

Same quality requirements for expert examination

The quality and commitment expected of court experts is explicitly provided for in the Dutch Code of Criminal Procedure. A separate part is dedicated to experts.6In the system of the current Dutch Code of Criminal Procedure, all technical investigating officers/experts of the national police force (hereinafter: the police) are entirely exempted from the NRGD quality guarantees that apply only to 'official' experts. For the precise legal considerations on which this is based, please refer to the explanatory memorandum. However, from a quality perspective, several arguments can made against such a 'formal' approach: 'Fundamentally, technical investigating officers are indeed experts, given that they use specific knowledge and skills in the course of their work.' And: 'The result of the current forced delineation of the concept of expert is that the supervision of the work of technical investigating officers is not regulated. No requirements are placed on the knowledge and skills of the technical investigating officers who conduct the technical investigation.7

The NRGD therefore believes that too great a difference is made (with regard to quality requirements) in the current system. This is particularly noticeable in areas in which both the NFI and the technical investigating officers draw up reports, such as in the interpretation of bloodstain patterns and digital investigations.

By now, the increasing importance of investing in high and guaranteed quality of the implementation of forensic investigations by the police is well recognised.8 The police themselves have also expressed their ambition to further improve quality assurance (see investigation development agenda, track 3, 2018).9

An exception has also been made in the current DNA Testing in Criminal Cases Decree. In Section 7, subsection 2, the decree grants the Public Prosecution Service the power to appoint experts independently even if they are not listed in the register, provided that the laboratory is accredited. This power should be limited to  investigations resulting in factual information. This is because accreditation is not concerned primarily with assessing the expertise of individual experts who make interpretations, as is the NRGD, but rather the suitability of the methods with which actual data is generated, such as DNA profiles.

The NRGD believes that interpretation of data should always be carried out by registered experts. If there is no registration, a non-registered expert must only be permitted to do this following an appointment by the investigating judge. In the view of the NRGD, it is essential for this aspect of criminal proceedings to be permanently guaranteed. The planned update of the Code of Criminal Procedure offers a unique opportunity to do so.

It goes without saying that unnecessary bureaucracy must be avoided. In order to strike the right balance, making the distinction between factual and interpretative investigation could be helpful. Factual investigation concerns the investigation of traces and the generation of data such as, a DNA profile, a fingerprint or transition mast data. Interpretation refers to evaluating the probability associated with findings in particular scenarios. This can include for example the interpretation of complex/mixed DNA profiles, complex fingerprints or the evaluation of digital data. This evaluation, in particular, can provide crucial evidence in criminal proceedings.

A quality assurance system for the entire chain

Here, the NRGD foresees the necessary challenges. The investigative possibilities offered by forensic science keep expanding. The available financial resources cannot keep pace with this trend. As a result, deciding how these limited resources are to be used is a constant balancing act, which can lead to conflicts when investing in adequate quality, among other things with training. As the former Forensic Science Regulator for England and Wales puts it:

'There are lots of other pressures such as the pressure to deliver on time and costs. I'd say that applies just as much to policing organisations and government organisations as it does to commercial ones. With all those pressures present, you need to make sure that there is an equal pressure on quality so that it doesn't end up as the weakest link.'10

In England, a Forensic Science Regulator has been introduced, who since 2021 has also statutory powers to conduct investigations into signs of shortcomings in quality assurance.11 The NRGD also advocates the expansion and legal embodiment in the Netherlands of a chain quality assurance system for forensic expertise, including an independent party who monitors/oversees the quality of the forensic chain as a whole, including the private market.


The NRGD has accomplished a great deal since its establishment: the adoption of quality requirements for twelve areas of expertise in consultation with the professional field, assessment and registration of experts, recognition of training programmes, advice to the forensic investigation chain and sharing of knowledge with the professional field. We are prepared, with reference to the analyses of the WODC, to cautiously conclude that the quality of expert contributions in the justice system has been better safeguarded over the last 12.5 years.

A hybrid quality assurance system has been developed that involves a variety of instruments, depending on the extent of the previous quality control:

  1. an individual assessment of the expert whereby other guarantees may not be relied upon; the NRGD performs the assessment itself;
  2. a system of recognition that enables institutes or professional associations to obtain recognition for their forensic training programme, by virtue of which the NRGD's assessment is no longer required and an assessment is only carried out at the body itself, with an external examiner from the NRGD on the Examination Board;


  1. a toolbox with which the use of ad hoc experts in the justice system can be improved.

One goal for the future is to realise a single register for the entire justice system, so that the quality of experts who work in administrative and civil law can also be better safeguarded. Another goal relates to the quality assurance of the entire forensic investigation chain with regard to interpretation of the investigative data gathered. We must continue to ensure that the quality of forensic investigation

* M.M.A. Smithuis MD, LLM is managing director of the NRGD.

  1. Experts in Criminal Cases Act (Bulletin of Acts and Decrees 2009, 33). This act has been incorporated into the Dutch Code of Criminal Procedure. The legal basis for the NRGD can now be found in Section 51k, subsection 1 of the Dutch CCP in conjunction with Section 4 of the Register of Court Experts in Criminal Cases Decree.
  2. Section 2 of the Register of Court Experts in Criminal Cases Decree.
  3. Section 4, preamble and under a, b, and c of the Register of Court Experts in Criminal Cases Decree.
  4. In this section it was decided to subsequently refer to the NRGD, where the Board would sometimes be formally more accurate.
  5. WODC report Evaluatie College gerechtelijk deskundigen (Evaluation of Board of Court Experts), repository.wodc.nl/bitstream/handle/20.500.12832/2468/3057_volledige_tekst_tcm28-455478.pdf?sequence=2&isAllowed=y 
  6. Book 1, Part IIIC of the Dutch Code of Criminal Procedure: Experts (Section 51 i-51 m of the Dutch CCP).
  7. R.A. Hoving, De deskundige in het gemoderniseerde Wetboek van Strafvordering (Experts in the updated Dutch Code of Criminal Procedure), Tijdschrift Modernisering Strafvordering 2020, issue 1, p. 18-25, quotes derived from p. 19.

  8. Forensic Investigation and Innovation Expert Group, Driejaarlijkse signalering. 30 maart 2016 (Three-year survey. 30 March 2016), annex to Parliamentary Papers // 201 5/16, 29279, No. 328.

  9. Parliamentary Papers II, 2017/1 8, 29628, No. 799.

  10. Interview met Forensic Regulator Gill Tully.
  11. Forensic Science Regulator Act 2021.