Forensic DNA databasing: Retention regimes and efficacy

Research Institution / Organisation

Northumbria University

Principal Researcher

Aaron Opoku Amankwaa

Level of Research


Project Start Date

October 2016

Research Context

The aim of this research is to develop forensic DNA data retention standards for the protection of public security and the individual’s right to privacy. This will be achieved by assessing the efficacy of the different retention regimes used for the England and Wales National DNA Database (NDNAD).

The specific aims to achieve the overall goal of this study are:

  1. To evaluate the overall performance of the NDNAD under the different retention regimes using two types of database match rates proposed by the DNA Working Group of the European Network of Forensic Science Institutes (ENFSI):   a) H/C or ‘crime-solving match rate’ (CMR); and b) H/N or ‘database-size match rate’ (DMR); where H is the number of hits or matches between subject and crime scene profiles, C is the number of crime scene profiles loaded on the database, and N is the number of subject reference profiles on the database. The performance metric H/C demonstrates the potential value of the database towards crime-solving whilst H/N indicates whether the database is representative of the active or previously active criminal population or individuals connected to a crime scene.
  2. To estimate and compare the annual H/C and H/N for different retention categories as defined by law (example, convicted adults versus non-convicted adults charged with a serious offence) within and between the applicable retention regimes.
  3. To estimate and compare the annual H/C and H/N for different subject profile retention time (years) from 1995 to present.
  4. To carry out a survey among NDNAD stakeholders to determine their effectiveness rating of the different retention regimes using a questionnaire. The objectives for this aim are to review the literature to identify effectiveness criteria that are relevant for assessing the efficacy of the different retention regimes; develop, test and refine the wording of questions based on the identified effectiveness criteria; assess the reliability and validity of the questionnaire; and administer the questionnaire to the study participants.

Research Methodology

​The first part of the research will involve a statistical analysis of historical NDNAD match rate (MR) data to determine the impact of the different forensic DNA retention regimes on the performance of the NDNAD.

The second part will involve a survey of staff, members or employees of 118 identified NDNAD stakeholder organisations/agencies/groups involved in the collection and processing of DNA samples, and use of the NDNAD; oversight and operation of the NDNAD; and those with a special interest in the operation/use of the NDNAD in England and Wales.

Interim reports and publications

​Publication currently under peer review.

Date due for completion

September 2019
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