Mark Gregory

Mark Gregory was a researcher for International Electromatics. He assisted in developing the Cerebration Mentor for use as a weapon against the Cybermen. After UNIT rescued Professor Watkins, the Cybermen shot and killed him. (DW: The Invasion)

His body was recovered by C19 and kept in frozen storage within The Vault. (DW: The Scales of Injustice)
 * Gregory's first name was not given on-screen, only in the novels.