R (on the application of GC) v Metropolitan Police Commissioner [2011] UKSC 21, [2011] All ER (D) 167(May)
The fundamental feature of s 64(1A) of the Police and Criminal Evidence Act 1984 was that it gave the police the power to retain and use data from suspects for the stated statutory purposes of preventing crime, investigation of offences and the conduct of prosecutions. But that did not justify a blanket or disproportionate practice. Neither indefinite retention nor indiscriminate retention could properly be said to be fundamental features of s 64(1A). Section 64(1A) clearly delimited the exercise of the discretion of the police to retain DNA data.
Such discretion had to be exercised to enable the data to be used for the statutory purposes and had to be exercised in a way which was proportionate and rationally connected to the achievement of those purposes. Parliament did not intend for there to be a scheme of indefinite retention in all cases. It intended that there would be a proportionate scheme which gave effect to the statutory purposes and which was compatible
