On the break of dawn of August 6, 1890, Kemmler awoke to his execution which was the first of its kind. After quickly donning a suit, having breakfast, and saying a silent prayer, his head was shaved. Kemmler was then presented to 17 witnesses who were in attendance and walked to his final seat. Witnesses attested to Kemmler being calm and composed before and during his execution.

However, the execution didn’t go as expected. The previous day, the chair had been thoroughly tested on a horse, and the process had been seamless. On this ill-fated day, the generator that was expected to transfer the electrical current was charged with 1000 volts because it was thought to be sufficient enough to induce a quick and painless cardiac arrest that would cause Kemmler’s death. The current was allowed to pass through him for 17 seconds, after which he was declared dead.

Witnesses, however, saw that he was still breathing, and in a bid to carry out the execution, they electrocuted him a second time with 2000 volts. This second attempt, however, was too much and led to an incredibly gory spectacle. Kemmler’s skin was completely charred, leaving a nauseating smell of burning flesh in the execution room.

William Francis Kemmler became the first person to be executed in an electric chair under New York’s new execution law that replaced hanging with electrocution. The method was thought to be more quick, painless, effective and humane. Kemmler was convicted for murdering Matilda Ziegler, his girlfriend, who was then considered his common-law wife.