Fingerprints and DNA samples are forms of identification evidence, which the police may use to link a suspect to a crime or crime scene. However, it is important to be aware of the circumstances in which the police are able to take such evidence.
A suspect’s fingerprints may be taken either with or without his consent under section 61 of the Police and Criminal Evidence Act 1984 (PACE); however, if the suspect is at the police station, consent must be given in writing.
Section 61 allows police to take fingerprints from a person who has been detained at the police station for a recordable offence (offences for which convictions, cautions, reprimands and warnings may be recorded in national police records), or charged with or convicted of such an offence. Fingerprints may also be taken from a person who has been given a caution, reprimand or warning for a recordable offence.
Outside the police station, an officer may take a person’s fingerprints if he reasonably suspects that the person is committing or attempting to commit an offence. They can also be taken if the officer suspects that the person has already committed an offence and the name of the person is unknown, cannot be ascertained, or the officer has reasonable grounds for doubting whether the name provided is real.
It is important to note that fingerprints taken in these particular circumstances cannot be retained after they have been checked.
The police can, under PACE, use reasonable force if necessary to take a person’s fingerprints without his consent.
Before fingerprints are taken, the suspect must be informed: why the fingerprints are being taken; the grounds relied on if the fingerprints are taken without consent; and that the fingerprints may be retained and made the subject of a speculative search.
Samples are divided into two types: intimate (such as a dental impression or a sample of blood, semen or urine) and non-intimate (such as hair other than pubic hair, a sample taken from a nail or saliva).
Under section 62 PACE, intimate samples require appropriate consent to be obtained in writing. They can only be taken on the authority of a police officer with at least the rank of inspector, who must have reasonable grounds for suspecting the suspect’s involvement in a recordable offence, and must believe that the sample will confirm or disprove this.
The suspect must be warned that their refusal to provide a sample without good cause may harm their case if it comes to trial.
These may be taken with the suspect’s written consent or, in some circumstances, without their consent. In these circumstances, the police can use reasonable force to take such a sample.
Before taking a sample of any kind from a suspect with or without consent, the police must inform them of: the reason for taking the sample, the grounds on which the relevant authority has been given; and that the sample may be retained and made the subject of a speculative search.
Retention of evidence
Fingerprints or DNA samples may be checked against other fingerprints and DNA samples which the police have obtained during the course of previous investigations to see if the suspect may be linked to other crimes. The police are allowed to retain fingerprints and samples taken during the course of investigation only in certain circumstances, such as when the suspect from whom the sample is taken is subsequently convicted of the offence. If the police are not permitted to retain the samples or fingerprints, then they must be destroyed.