In episode eight of our Case Studies season, Just Science sat down with Brian McVicker, a Forensic Footwear and Tire Examiner at the Federal Bureau of Investigation (FBI), to discuss developing shoe and tire impressions on fabric using ninhydrin. When a victim is stomped or runover, the transfer of skin cells onto the inside of the victim’s clothing can leave an impression of the shoe or tire that was used. Due to the valuable information this can provide to investigations, the FBI Laboratory’s Footwear and Tire Group performed a validation study exploring the efficacy of ninhydrin to develop footwear or tire impressions on the inside of clothing, specially focusing on using an iron as a heat source and dark fabrics. Listen along as Brian describes how the study has expanded existing ninhydrin processing procedures, scenarios in which ninhydrin processing would be helpful to a case, and the value of involving interns in this type of research. This episode is funded by the National Institute of Justice’s Forensic Technology Center of Excellence (Award No. 15PNIJ-21-GK-02192-MUMU). Some content in this podcast may be considered sensitive and may evoke emotional responses or may not be appropriate for younger audiences.