Kidman Deveraux was born into the Deveraux mafia family. He grew to become a doctor and then was recruited for the army to fight in an undocumented war. Along this process, he became a black market arms dealer and was interested in using biological weapons. Shortly after Professor Wilkens was cured of the Stigma infecting him, Kidman kidnapped Prof Wilkens and stole data relating to Stigma research, setting fire to Prof Wilkens’s office. With the help of Master Vakhushti, a mind control device was installed on Prof Wilkens’s brain, causing Prof Wilkens to assist Kidman with his Stigma research and development.
Over the course of the game, Kidman gradually releases more strains of Stigma, mainly Soma and Ops. Later on, Kidman's cronies kidnap Markus Vaughn, Valerie Blaylock, and Elena Salazar, in order to help him test the new Stigma Onyx. After failing to convince them to help him conduct further biological experiments, Kidman locks them in a slowly flooding cell, convinced that they will eventually cooperate.
After the surgeons escape, he and his henchman Leland go to Culuruma and aid the guerrilla leader Ramsey Ramirez in their rebellion against the government in hopes of obtaining the mining rights to the Culurium mines (said material is crucial in the creation of Stigma). After the raid on Wanadeo Base, he was ultimately killed by the government forces. Kidman's liver was eventually used to save the surviving Ramsey Ramirez and Leland.