In the Jokers first appearance, hes not quite the wacky loon he would become in later appearances; however, hes murderous as ever. Making his presence known via a radio announcement, the Joker declares his intention to kill millionaire Henry Claridge that very night at midnight and steal his famed Claridge Diamond. Despite the battalion of police guarding the millionaire, at the stroke of midnight Claridge drops to the floor, dead, with his facial muscles pulling back into a hideous smile.
Furthermore, the police find that the diamond is already gone, having been replaced by a glass phony, accompanied by a playing card bearing the Jokers likeness. As it turns out, the Joker had committed the crime the night before, injecting Claridge with a version of his Joker venom that takes 24 hours to take effect.
The Joker strikes again later that week, with a radio promise to steal the Ronkers Ruby and murder its owner. This time, the Joker, hiding inside an ornamental suit of armor, kills with a poison dart gun bearing his deadly Joker venom.
The Batman first encounters the Joker while attempting to stop the murder of Gotham gangster Brute Nelson, who had been badmouthing Gothams newest criminal.
Joker proves to be a physical match for Batman, and the Joker manages to escape, and goes on to make his next radio threat, this time to Judge Drake, who had once sent him to prison. While the Judge seems safe, under the personal protection of Gothams Chief of Police, things are not always what they seem.