Using DNA as biological evidence

DNA is found in most cells of the human body.

A person’s DNA is the same in all cells.

In other words, regardless of the type of sample, you should get the same result.

People leave our DNA lying about all over the place, which means that forensic scientists can obtain DNA from:

  • Blood
  • Semen
  • Saliva (such as on cigarette butts and used drink bottles or cups)
  • Hair (with roots)
  • Teeth
  • Bone
  • Tissue
  • Skin cells (left on clothing)
  • DNA samples can be collected from surfaces at a crime scene that people may have touched or from objects, like the cricket bat or the bloodied sweatshirt in case one. DNA samples can also be collected from people who may be suspects or want to be eliminated from suspicion

Find out more about how Police use DNA as evidence:

ESR’s DNA techniques available for use in forensic case work (1.5MB pdf)