Fans of true crime documentaries hear the terms all the time: bloodstain patterns, ballistics evidence, and sniffer-dog searches.While these methods are commonly believed to provide solid evidence, new research from the University of British Columbia finds that they may not be as useful as previously thought.This could mean that what investigators and courts treat as solid evidence may be anything but, the study found.“Just because a technique has been used in court for decades doesn’t mean we should take its reliability for granted, especially when someone’s liberty is at stake in a criminal trial,” said study author Sara Gordon, associate professor at Peter A. Allard School of Law at UBC.“My hope is that this research will help judges and lawyers better understand the limitations of these techniques and ensure that forensic evidence is presented in a way that accurately reflects what the science can — and can’t — tell us.”Gordon says the use of ballistics evidence — which involves matching bullets and cartridge cases to a particular firearm — is a good example. In a test, the study found that investigators misidentified bullets 37 per cent of the time.She says bloodstain pattern analysis is another form of evidence that Canadian courts treat as solid proof, but practitioners often use concepts like fluid dynamics without necessarily having any training in physics.“If you dig a little deeper, you start to see that the field rests on a much shakier scientific foundation than courts have often assumed,” she said.“There haven’t been many rigorous scientific studies, and the studies that are now emerging suggest that many of the conclusions police officers have testified to in court are not supported by the science.”UBC says one study found analysts were correctly classifying bloodstain patterns only 70 per cent of the time on solid surfaces. On fabrics, that number dropped to 62 per cent.Gordon also says the use of drug-detection or sniffer dogs can lead to inaccurate results. The researchers point to a study conducted in Australia that found nearly 75 per cent of police dog alerts turned out to have been unfounded. Gordon says clearer standards for training, certification, and performance monitoring are needed.The researchers call on judges to make sure expert evidence used in court is supported by science. They also call for greater scientific literacy among lawyers and judges.