DNA samples and identifying information

DNA is a substance that is part of every human body. It is different for everyone, except identical twins.  Scientists can analyse your DNA to create a DNA profile that is specific to you. Fingerprints are also used to help identify people.

Your DNA profile or fingerprints might be used in court as evidence about whether or not you were the person who committed an offence. The police might have DNA or fingerprint evidence from an offence. The court will be told whether or not your DNA profile and fingerprints matches what the police found, and how likely it would be that it was someone else's DNA profile or fingerprints and not yours. 

Your DNA profile can also sometimes be used to show that you did not commit a particular crime.

When investigating offences, the law says you may be asked or required to give a DNA sample to police in certain circumstances. The police may also have the right to take your photograph or fingerprints.

This information will help you to understand more about DNA samples and identifying information.  Find out:

  • How can a DNA sample be taken?
  • Do I have to give a DNA sample?
  • What happens to my DNA sample after it’s been taken?
  • Can police ask me for any other identifying information?

How can a DNA sample be taken?

  • Mouth cell sample
  • Hair sample
  • Blood sample

Police must use the least painful method available.

Do I have to give a DNA sample?

If police ask for a DNA sample, you can decide whether or not you consent. If you are under 18, a responsible adult can consent or refuse on your behalf.

If you don’t consent, you can still be required by law to provide a sample if:

  • you are suspected of or charged with committing an offence that has imprisonment for 12 months or longer as a possible penalty, or
  • you’ve have been convicted of a serious offence in the last 6 months.

If you refuse to give a sample when required by law, police can use any force that is reasonably necessary to obtain the sample.

What if I am a victim or a witness?

You might be asked to provide a DNA sample in the form of a mouth swab or hair from your head. 

If you are an adult, you can choose whether or not to consent to giving a DNA sample. You cannot be forced to give one.

If the police want a DNA sample from a child, a a responsible person for the child refuses to give consent, the police will need to have a warrant before they can take a DNA sample without consent. 

What happens to my sample once it’s been taken?

It will be analysed in a private laboratory to get your DNA profile. This will be stored in a computer database and can be accessed by police around Australia to compare with DNA profiles found at crime scenes.

You can ask for your DNA profile to destroyed if:

  • you are found not guilty or your convicted is quashed
  • you were a suspect and never charged, or
  • you were a victim or a witness.

Otherwise, it will be kept forever.

What other identifying information can the police obtain?

The police can ask your consent to take:

  • prints of your hands, feet, or ears
  • photographs of you, and
  • measurements or impressions of any identifying features.

If you don’t consent, you may still be required to provide the information in certain circumstances.



More information


The information displayed on this page is provided for information purposes only and does not constitute legal advice. If you have a legal problem, you should see a lawyer. Legal Aid Western Australia aims to provide information that is accurate, however does not accept responsibility for any errors or omissions in the information provided on this page or incorporated into it by reference.