Commander Simon Foy, head of the Metropolitan Police's Homicide and Serious Crime Command, Specialist Crime Directorate wrote an appalling comment piece titled DNA database keeps us safe in The Guardian. It includes this paragraph:
The decision about whether to remove the DNA of those who are yet to be convicted of an offence will rightly be made by politicians. In the past the police have made the case to government for retaining these samples and they have agreed, but the EU case may change that. Obviously Jeffrey's knowledge and grasp of the scientific details surpasses mine, I'm just an investigator but the reality for me is the more people on the database, the more effective our investigation will be. [Emphasis added]
Letting pass that it wasn't a EU (in Brussels) case but a European Court of Human Rights (in Strasbourg) judgement, the court found 'that the blanket and indiscriminate nature of the powers of retention of the fingerprints, cellular samples and DNA profiles of persons suspected but not convicted of offences [...] fails to strike a fair balance between the competing public and private interests and that the respondent State has overstepped any acceptable margin of appreciation in this regard.' [Emphasis added] That adding more profiles of individuals on the database helps to solve more crime has been debunked by GeneWatch UK.
Commander Simon Foy is writing about individuals who have been suspected and hence arrested but not convicted of any offences - either because no further action was taken or because they were acquitted after having been charged. These are individuals who are innocents.
The rest of the article is poor as well, but that someone of the rank of Commander can condemn innocents as 'yet to be convicted' is really crass. This demonstrates that in the eyes of the police the National DNA Database (NDNAD) is a crime-related intelligence database.