DNA samples

Police can take samples from people charged with, or suspected of, committing a serious offence that carries a statutory penalty of 12 months or more, regardless of the actual sentence imposed.

What is DNA?

DNA (deoxyribonucleic acid) carries genetic information passed on to you from your mother and father and determines your physical characteristics.

A DNA sample is a collection of cells from your body. The type of sample that police usually collect from you is a buccal swab (a mouth swab). The law also allows police to take other samples, such as hair or blood in some instances if you don't agree to give a mouth swab.

How is a DNA sample taken?

If the sample is by mouth swab, it simply involves wiping a swab inside your mouth. You will be asked to do the mouth swab yourself, under police direction. The swab is like a large cotton bud and does not hurt you.

When a sample of hair is required, police will pull a number of hairs from your leg, arm or head.

If difficulty is experienced in obtaining either of these samples, police are authorised to take a sample of your blood. This is a simple finger prick blood sample, which some police are qualified to do.

All of these procedures are simple and will not harm you.

What happens next?

A DNA profile is obtained from the sample. The profile is then recorded on a DNA database. It will then be compared with DNA samples collected from crime scenes to see if they match. Your DNA sample will not be tested for drugs.

Sample use and destruction

If you volunteer your sample, you may decide whether to:

  • limit the purposes for which it is used, or
  • allow it to be used for unlimited forensic purposes.

You may also decide how long this information may be held by police.

As a witness or a victim of an offence, you may decide whether to:

  • limit the purposes for which your sample may be used, or
  • allow the sample to be used for unlimited forensic purposes.

If you are a suspect for an offence then you may request your identifying particulars be destroyed if, after two years:

  • you have not been charged with a relevant offence; or
  • you are found not guilty of the offence you were charged with.

If you have been charged with a serious offence, you may request your identifying particulars to be destroyed if you are found not guilty of the offence you were charged with.

Sample destruction

If you wish the sample to be destroyed, either you or your legal representative need to make a request in writing to: Commissioner of Police Police Headquarters 2 Adelaide Terrace East Perth WA 6004

Where can I get help?

Contact your legal representative, Legal Aid or the Aboriginal Legal Service as soon as possible if you have any concerns about consenting to a DNA sample being taken.