Online exclusives

'What was once impossible now seems routine'

The evolution of DNA

By

Just 25 years ago, Canadian courts were uncertain about accepting DNA and the claim that it would provide irrefutable evidence. Compare that to today, when prosecutors and investigators actively focus on the availability of DNA to help their cases. Processing DNA profiles has moved from a time-consuming, labour-intensive method to one that is largely automated and conducted by hundreds of scientists and technologists in Canada.

In 1989, a suspect changed his plea mid-trial to guilty after hearing DNA evidence that confirmed he was the perpetrator of a sexual assault. A watershed moment quickly followed in 1991 when Allan Legere, known as the "Monster of the Miramichi," was convicted of serial murder — largely due to DNA evidence.

At that time, the RCMP had only a handful of research scientists doing manual DNA processing. "It was an interesting time," says Dr. Ron Fourney, the director of Science and Strategic Partnerships, which includes oversight of the National DNA Databank. "The issue has moved on from 'what is DNA all about?' to 'what do you mean there is no DNA associated with the crime?' "

The way DNA is used for investigations and in courts is not so different from the way the Internet has evolved. The World Wide Web was invented in 1989 and today, many people cannot do without accessing it on a daily basis.

Likewise, DNA has pushed the envelope with respect to limitations. In today's world, courtrooms actively seek hard evidence, like DNA, to provide an impartial explanation of evidence that is collected at crime scenes. One of the biggest problems is managing expectations — not every crime scene generates biological exhibits. Experienced crime scene investigators are critical for obtaining successful DNA results, and good evidence collection initiates the process.

In 1989, a blood sample the size of a quarter used to be needed to develop a DNA profile. Today, a sample of approximately 40 cells, or roughly 10 per cent of what would fit on the head of a pin, is all that's required. Due to technological advances and a better understanding of DNA, scientists are able to develop quality-assured DNA profiles quickly, often from the most challenging biological samples, such as those derived from degraded evidence or composed of more than one biological donor.

What's next for DNA? With technological innovation and automation, forensic science will eventually move as close as possible to the front end of the investigation.

In a more direct and mobile manner, there is the likelihood for DNA analysis to be at the fingertips of investigators in the field and will help focus the scope of the investigation from the very start. This would not only serve the police more effectively, but it would also help identify, eliminate and exonerate suspects sooner.

"The history and future evolution of DNA is limited only by imagination, innovation and dedication," Fourney says. "What was once impossible now seems routine."

Reprinted with permission from the Pony Express (No. 2, 2014).

Date modified: