Toby Stevens has come to realise why he has always been worried about population wide dna databases but until now not been able to articulate his reasons.
"Where the real problems will arise is in the handling of minor offences. Based on a case given in the documentary, picture this scenario: your DNA was taken some years ago when the police accused you of some youthful vandalism, but no charge was pressed because the true culprit was identified after the arrest. At a later date, you are arrested for stealing mail because your DNA was found on a number of letters recovered from a skip. The police inform you that this is a minor offence in their opinion, and if you accept a caution they will not press matters. You refuse because you are innocent. Only later, after a lot of trouble, does it transpire that your DNA was on those letters because you had posted them yourself.
Now, if you had accepted the caution in order to gain release from police custody, the authorities would have given you a criminal record, and not investigated further, believing the case to be closed. This, I understand, is a common situation that is driven by 'policing by numbers' policies. Unfortunately many people do not understand the implications of a caution, believing it to be the equivalent of a friendly cuff round the ear from the village bobby when caught scrumping apples.
This scenario worries me a lot, and I now understand why I'm concerned about the collection of large numbers of DNA samples, particularly when there appears to be no clarity about how it might be used in the future."