What happens when someone is arrested.

The Liberty website has a good general guide to what happens when someone is arrested and explains a person's rights.

The process of obtaining a DNA sample usually begins at a police station when an officer takes a tissue sample from a newly arrested person. The police first check the Police National Computer (PNC) to see if the individual's DNA profile is already on the NDNAD - a fresh sample is not taken if an existing profile is confirmed. Most often a sample is obtained via a mouth swab - a large cotton wool bud is rubbed inside the suspect's cheek to loosen and collect skin cells. Alternatively, ten hairs with roots can be removed from the head. The sample is then put into a small plastic tube which is sealed. The process is repeated so that there are two samples for each suspect.

Code D of the Police and Criminal Evidence Act (PACE) 1984 and its Codes of Practice (as amended 2005) stipulates when and how the police can take DNA samples from an individual. They only have a right to take both intimate (such as blood or urine) and non-intimate samples (such as hair or cheek swabs) 'only when justified and necessary for preventing, detecting or investigating crime'.

The police can take non-intimate samples if a person has been arrested for a recordable offence (this includes begging, being drunk and disorderly and taking part in an illegal demonstration). The DNA does not have to be relevant to the offence for which a person is being arrested and they do not have to be charged before the sample is taken. The police are not allowed to take more than one 'successful' sample from the same body part during the course of an investigation.

The police can take an intimate sample only with a person's written consent even if they have been arrested.

Once a DNA sample is taken, it is stored, processed and the person's profile is added to the National DNA database. This will happen irrespective of whether the person is charged and/or prosecuted. The legal power to do this is with the Chief Officers of each Constabulary. The law gives them the right to add a person's DNA to the database but does not oblige them to do so. This is the same for fingerprints and for entries on the Police National Computer (the PNC).

The information included on the National DNA Database is:

  • the Arrest Summons Number (which provides a link to the record on the PNC)
  • the person's name
  • their date of birth
  • their ethnic appearance
  • their sex
  • information about the police force that collected the sample
  • information about the laboratory that analysed the sample
  • the sample type (blood, semen, saliva etc.)
  • the test type
  • the DNA profile.

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