Dr. Gavin Dexter was the Head of Research at Pangbourne Scientific Lab.
Ironically, he was not using animals, but human subjects. He was also affiliated with the Crimson Chapter of the Orbus Postramo -- a doomsday cult. He crafted a variant of the virus that grew fifty times faster, which the Chapter wanted to release to bring about the apocalypse they believed was predicted in the Book of Tomorrows.
When Will Sullivan was sent to get the antidote to the virus from Dexter, the Keeper of the Crimson Chapter had him kill the doctor on the pretext that he might be a sleeper agent for the rival White Chapter. Afterwards, she admitted he was likely innocent, but thought he was too ambitious. (AUDIO: Fatal Consequences)