Chemistry At The Centre Of Forensic Science

The study of forensic science first began in Canada, in April of 1859, when Professor Henry Holmes Croft testified at the trial of Dr. William Henry King. Professor Croft testified that he had found eleven grains of arsenic in the stomack of Mrs. Sarah King. It followed that Dr. King was convicted of the murder of his wife. The main goal of forensic science is to provide scientific support for the investigations of injury, unexplained deaths and crimes. The chemistry division of forensic science deals with substances such as paint, glass, soils, metals, explosives, petroleum products, and plastics.

One basic principle of forensic chemistry is the underlying fact that every contact leaves a trace. If a hit-and-run were to occur there would be paint transfer; if a burglar broke a glass window, bits of the glass would be found in the burglar’s clothing; firing a gun would leave gunshot residue on the user’s hands.

Forensic chemists first find the clues. The clues are then analyzed and their significance is determined. In one case of a hit-and-run accident, a paint smear on the victim’s pants was found to be a silver metallic paint. From glass bits found on the victim it was determined that the rear window in the car had been smashed on impact. It was also observed that there was a partial impression of a Datsun logo on the victim’s pants. From this evidence, the vehicle was quickly located.

The most recently addition to the chemical services provide by forensic work in DNA profiling. This method has the capability of identifying the source of a body fluid with virtual certainty.

A single investigation in a forensic laboratory may involve many kinds of scientists. There are chemists, toxicologists, biologists, molecular biologists, botanists and geologists, just to mention a few. These scientists "detectives" piece together a very difficult puzzle to form a picture of the crime.

Forensic science in Canada continues to grow and expand. Today there are nine forensic science centres in Canada, including the RCMP labs. So when you read headline where a big case has been broken and many answers have been found, try to think about all the science and scientists, including chemists, who helped solve the case.