Can Police Take DNA or Other Samples From a Sexual-Offence Suspect?

What samples may the police request?

In an investigation involving an allegation of rape, sexual assault or another serious sexual offence, investigators may seek material for comparison with forensic evidence. This may include fingerprints, a mouth swab for DNA, hair, nail material, bodily swabs, blood, urine or other samples.

The rules are principally governed by the Police and Criminal Evidence Act 1984 (PACE) ↗ and PACE Code D ↗.

Intimate and non-intimate samples

PACE distinguishes between two important categories:

• Non-intimate samples include saliva, hair other than pubic hair, nail material, most external body swabs and certain skin impressions. A mouth swab used to obtain a DNA profile is normally a non-intimate sample.
• Intimate samples include blood, semen, urine, pubic hair, dental impressions and swabs from a person’s genitals or from a body orifice other than the mouth.

The classification matters because the police powers, consent requirements and method of taking the sample are different.

Can police take a sample without consent?

A non-intimate sample may be taken without consent in circumstances authorised by PACE—for example, from a person detained following arrest for a recordable offence, subject to the statutory conditions. Reasonable force may be used where the law permits a non-intimate sample to be taken without consent.

An intimate sample generally requires the suspect’s written consent as well as authorisation by an officer of at least inspector rank on the required grounds. Before asking for an intimate sample, the police should explain the reason, the power being relied upon and the possible consequences of refusing without good cause. Most intimate samples must be taken by an appropriately qualified healthcare professional.

Do not assume that every request is optional—or that every request must be accepted immediately. Ask what sample is sought, why it is required and under which legal power.

Should I speak to a solicitor before providing a sample?

Yes. A criminal defence solicitor can check whether the correct power and procedure are being used, explain the consequences of consent or refusal, and ensure that your position is properly recorded. Refusal of an intimate sample without good cause may, in some circumstances, allow a court to draw an adverse inference. Equally, providing a sample can have important evidential consequences.

Free and independent legal advice is normally available at the police station. Asking for a solicitor is not a sign of guilt. Ghafar Khan can advise suspects during arrest, detention or a voluntary police interview and assess the request alongside the wider evidence.

What happens to DNA and fingerprints afterwards?

Fingerprints and a DNA profile may be checked against police databases. Retention depends on matters including whether the person is charged or convicted, their previous record and whether the allegation is a qualifying offence. Where a person is arrested but not charged, material is often deleted, but the police can seek extended retention in specified cases. Read the government’s biometric-retention guidance ↗.