Senior Researcher Ronson was the first living being killed by a Dalek.
When Davros attempted to have a Dalek test its gunstick on the Fourth Doctor and Harry Sullivan, Ronson interceded, claiming he wished to interrogate them. Davros demanded he be punished for insubordination, after he had finished his questions.
During the subsequent interrogation, he revealed to the time travellers that he was opposed to the creation of the Daleks. He thought that Davros had deliberately withheld a conscience from his new creations, and that Daleks were totally "evil". He then helped the Doctor and Harry escape captivity, giving them a list of government officials who might be able to help them shut down Davros' Dalek project.
Shortly thereafter, Davros, realising what he had done, branded Ronson a traitor and ordered his Daleks to kill him. The extermination happened swiftly, and the test of that earliest gunstick was completed to Davros' satisfaction. (TV: Genesis of the Daleks)