Far from the sure-fire way to catch criminals it appears to be on television, the misapplication of forensic science is actually one of the biggest contributing factors to wrongful convictions. Research has shown that many forensic techniques applied in criminal investigations are not reliable, despite being portrayed to a jury as strong evidence of guilt.
For example, bite mark comparisons are notoriously inaccurate. This is a method in which someone trained in forensic odontology tries to match bite marks at crime scenes or on victims with dental impressions taken from a suspect. Hair matching is equally unreliable. The FBI has admitted that it exaggerated the ability to match hair samples for decades, misleading jurors or outright lying about how reliable such evidence was.
Forensic analysis is at risk for mistakes
Even when the underlying method is more reliable, forensic experts can still make mistakes. These can be accidental, such as mixing up samples or contaminating a specimen. While not common, some forensic labs and experts have also fabricated results or hidden evidence.
Will new federal rules improve the use of forensics?
Due to the well-documented problems facing forensics, the U.S Department of Justice announced new policies aimed at improving the standards and values around forensic analysis. The DOJ announced its new policies in February.
The DOJ intends to implement uniform language use policy which will require all forensic experts in the country to use standard language about reliability when giving testimony in court. Department labs will now be required to post all reports of their quality management records online.
It remains to be seen whether the introduction of these new policies will have any significant impact on the day-to-day practice of forensics. Hopefully, it will help innocent suspects better defend themselves in court and lead to a better way of finding out the truth.