DNA evidence

The conviction of Peter Tobin for the murder of the schoolgirl Vicky Hamilton after 17 years, during which her fate remained a mystery, is the latest example of how essential a tool DNA evidence has become in solving crime.

The idea that Tobin's DNA - and that of others who have committed serious, violent or sexual crimes - should be permanently stored on a database is not only practical but entirely just. By breaking the most basic bonds of society, such criminals have forfeited some of their rights. Storing DNA samples of entirely innocent people in order to be able to check them against possible future crimes, however, is an entirely different matter. In the case of DNA taken from people suspected of committing an offence, but subsequently cleared or where no proceedings are taken, retaining samples is tantamount to branding them as suspect in defiance of the course of justice.

In a case brought by two Englishmen whose DNA and fingerprints were retained by the police, despite one having proceedings against him dropped and the other cleared of a charge made against him when he was a child, the European Court of Human Rights has ruled that their right to privacy was breached. It is a fundamental tenet of British citizenship that we are all innocent until proven guilty; the rapidly growing database of DNA material gathered and stored by the police in England, Wales and Northern Ireland, not only from convicted criminals, but from suspects, suggests they would prefer to work from a presumption of possible guilt. That, as 17 European judges have ruled, is a breach of human rights. It is alarming that Home Secretary Jacqui Smith continues to defend the retention of samples. They do, as she argues, "play an invaluable role in the fight against crime", but that must be balanced against the rights of citizens, including victims, whose material can also be stored indefinitely. Several senior police officers, enthused by the prospect of short-circuiting time-consuming investigations, have called for a national database containing the DNA of the entire population. Among their number is Stephen House, the chief constable of Strathclyde Police, although Scottish police forces destroy the DNA records of suspects who are not convicted, unless criminal proceedings have been raised against them for a sexual or violent offence.

It can be argued that it is fairer to have a bank of everyone's DNA than one which consists of a mixture of convicted criminals and innocent people, but that does not deal with the basic principle that keeping such records is an invasion of privacy and, in practical terms, the government's recent failure to secure databases and protect personal records means there is considerable concern over security. Without confidence that DNA material is being handled in accordance with agreed principles and human rights law, fewer people will be inclined to provide samples for the purposes of elimination during a police inquiry and victims of crimes such as rape may be less likely to report them. Effective policing depends on cooperation from the public and that is not achieved by breaching privacy and treating everyone as a suspect.