In 2009, the US National Research Council Committee on Identifying the Needs of the Forensic Sciences Community published a report highlighting the need to estimate the validity of expert opinions in forensic disciplines. These include the opinions of firearm examiners, who are trained to identify firearms and other weapon-related evidence during criminal investigations. Dr Susan Vanderplas at the University of Nebraska Lincoln has recently introduced a new unifying approach for accurately calculating the error associated with firearm analyses. Her method could be applied in forensic laboratories worldwide, to improve the reliability of forensic evidence in criminal investigations.