During 1827 and 1828, Burke and Hare brought a new dimension to the trade of selling corpses "to the doctors" by murdering rather than grave-robbing and supplying their victims' fresh corpses for medical dissection. Their activities, and those of the London Burkers who imitated them, resulted in the passage of the Anatomy Act 1832. This allowed unclaimed bodies and those donated by relatives to be used for the study of anatomy, and required the licensing of anatomy teachers, which essentially ended the body snatching trade. The use of bodies for scientific research in the UK is now governed by the Human Tissue Authority.