If you’ve watched CSI, you might think DNA evidence is the ultimate smoking gun that solves every case. While DNA certainly plays a crucial role in criminal proceedings, the reality is far more nuanced than what television portrays. Understanding how DNA evidence actually works in NSW criminal cases can help you navigate situations where you or someone you know might be affected by DNA-related allegations.

What DNA Evidence Can and Cannot Tell Us

DNA evidence forms an important part of modern criminal investigations, particularly in serious matters such as assault, murder, and sexual assault cases. However, one of the most common misconceptions is that DNA evidence provides absolute proof of guilt.

The reality is quite different. DNA evidence typically forms just one piece of a larger puzzle. What DNA really confirms is that there was some form of contact between an accused person and another person, place, or object. It doesn’t necessarily determine the manner of that contact or explain what actually happened.

Types of DNA Evidence in Criminal Cases

Specific DNA Samples

In some circumstances, the quality of a DNA sample allows scientists to identify specific biological material such as saliva or semen. This type of evidence can be more telling about the nature of contact between parties.

For example, in sexual assault cases where specific DNA such as semen is found on or in the complainant, this could constitute strong evidence of sexual contact, assuming the DNA evidence is proven credible. However, even in these circumstances, DNA cannot determine whether the contact was consensual.

General DNA Matches

More commonly, investigators find “general” DNA material at a crime scene, on an item, or on a person that matches an accused individual. This DNA match may form a critical part of the prosecution’s case, especially when an accused person claims they were not present at the scene or denies the alleged conduct.

The Reality of DNA Transfer

Innocent Transfer

It’s extremely common for DNA to transfer between people who have come into contact with one another without any criminal conduct occurring. Simple actions like shaking hands or hugging someone in greeting will almost always result in DNA transfer.

Secondary Transfer

DNA can also move from one person to another without any direct contact between them. This phenomenon is known as “secondary transfer.”

Consider this scenario: if someone opens a door handle and a second person later opens the same door, DNA from the first person can transfer from the handle to the second person, despite the two individuals never having direct contact. In criminal investigations, the individual circumstances of each case determine whether secondary transfer might explain how someone’s DNA ended up at an alleged crime scene.

How DNA Evidence Impacts Criminal Defence

When DNA evidence appears in a criminal case, experienced legal representation becomes crucial. A skilled criminal lawyer will examine:

• The chain of custody for DNA samples
• The quality and reliability of testing procedures
• Alternative explanations for DNA presence, including innocent transfer
• Whether the DNA evidence actually supports the specific charges

The presence of DNA evidence doesn’t automatically mean guilt, but it does mean you need someone who understands both the science and the law to properly assess your situation.

Need Legal Advice About DNA Evidence?

If you’re facing criminal charges involving DNA evidence in NSW, don’t navigate this complex area of law alone. At Complete Legal, we understand how DNA evidence works in practice and can help you understand your options with clear, straight-talking advice.

Contact us today to discuss your situation with experienced criminal lawyers who will have your back when it matters most. Book a consultation to get the dedicated legal support you need.