Forensic entomology: The Song Dynasty (960–1279) forensic science work Collected Cases of Injustice Rectified published by Song Ci in 1247 contains the oldest known case of forensic entomology.[312] In a murder case of 1235, a villager was stabbed to death and authorities determined that his wounds were inflicted by a sickle; this was a tool used for cutting rice at harvest time, a fact which led them to suspect a fellow peasant worker was involved.[312] The local magistrate had the villagers assemble in the town square where they would temporarily relinquish their sickles.[312] Within minutes, a mass of blow flies gathered around one sickle and none other, attracted to the scent of traces of blood unseen by the naked eye.[312] It became apparent to all that the owner of that sickle was the culprit, the latter pleading for mercy as he was detained by authorities.[312]