Bill proposes wider DNA sampling
A new Bill, the Criminal Investigation (Bodily Samples) Amendment Bill, had its first reading in Parliament on 10 February 2009. Politicians debate new Bills to examine the pros and cons. If the politicians agree to the Bill, it will pass into law as an Act.
This proposed Bill will allow DNA to be taken from anyone arrested and charged with an imprisonable offence. The DNA will be added to New Zealand’s National DNA Database (NDD), which, as at January 2009, contained the DNA of more than 90,000 people.
Using DNA to help solve crimes
At present, DNA in the NDD is from people who have been convicted of certain types of crime or who have been compelled to give a sample under the existing Criminal Investigation (Bodily Samples) Act 1995 or from those who have volunteered samples.
This DNA is usually compared to a second database of unknown DNA, the Crime Sample Database (CSD), which contains DNA from biological samples collected at crime scenes. The CSD is also matched against itself so that any links between unsolved cases can be identified.
The Crime Sample Database Unit (CSDU) at Environmental Science and Research (ESR) often works on cases where there are no leads for the police other than a small amount of biological material that has been left at the crime scene. Matching between the CSD and NDD results in about 90 previously unknown links between individuals and crimes per month.
Identification of DNA at a crime scene does not prove a person’s innocence or guilt in a case. A jury decides this based on all the evidence of a case. A person may have a perfectly legitimate reason for being at a crime scene. They may not have even been there at the time the crime took place.
ESR scientists can extract DNA from many different types of biological material collected by police. These samples include blood, sperm, hair roots, skin, other body tissue and sometimes even saliva and sweat.
Concerns about the proposed Bill
Some people are concerned about the new Bill before Parliament, believing that it is a step towards a surveillance society. If you’re not sure how DNA sampling could lead to this, watch the movie Gattaca. Prime Minister John Key said DNA testing was the "modern-day fingerprint". "DNA testing has been proven to be highly effective in matching people with previous crimes that they otherwise haven't been convicted for," he said.
Learn more about how DNA samples are handled in New Zealand, including the specialised equipment and laboratories that are used.
Visit the Biotechnology Learning Hub to learn more about the role of DNA in modern forensic science.