The Role of DNA Evidence in Assault Trials

The role of DNA evidence in assault trials can be very important depending on the seriousness of the assault, the budget of the lawyers involved, and the specific evidence available in a given case. Sometimes a lawyer may want to use DNA evidence to implicate a defendant, and another lawyer may want to use DNA evidence to show just the opposite—that an individual could not be the party responsible for a crime or that there is doubt whether a specific person committed a crime.

In today’s blog article, we want to talk about DNA evidence and how it might or might not be used in an assault trial. Whether or not this type of evidence is used would depend on whether it is even available, whether it is possible to obtain an expert witness to speak to it, and whether the stakes are high enough to warrant paying a DNA expert witness to testify to it.

Is there DNA evidence?

DNA evidence can only be used in a criminal trial if it exists. While many juries are swayed by the “CSI Effect” and like lots of technical evidence, most trials do not have lots of microscopic evidence that can be used and are what we call circumstantial cases that are decided by common sense.

Is the evidence usable?

And then there is the question of whether the evidence is good evidence or whether there is or might be any contamination. If the defence or prosecution does not like what the DNA evidence points to or how it was collected or handled, either side may argue that the evidence was not handled properly and should not be relied on.

Expert witnesses?

Then there is the question of whether there is an expert witness who can interpret the evidence for the judge or jury. DNA evidence is not very valuable if no one understands what it means.

So, the importance of DNA evidence in an assault trial depends on a number of factors. The type of evidence may not be available or even collected in minor cases with small charges. However, an assault case that includes a seriously injured victim is much more likely to have had careful evidence collection and at least the possibility of DNA evidence available to interpret. 

Gagan Nahal is a criminal defence lawyer based in Surrey, British Columbia, although he has represented clients across Canada. He works vigorously and tirelessly defending his clients. 

If you have any questions about this article or you would like to talk to Mr. Nahal, please call him directly at (604) 527-4769.