Smoking Gun: Conclusive Evidence (2014)

Researchers at the investigation lab solve cases using the latest scientific techniques including DNA testing, image analysis, handwriting analysis and fingerprint contrast. Enishi Nagareta works at the private investigation lab. He tries to solve small cases which the police may have overlooked. One of his favorite tools is asugary donut. At the site of the incident, Enishi finds clues by looking through the hole of the donut.