The trial of Yakone was the proceeding in which the bloodbending criminal Yakone was sentenced to life in prison for using his outlawed ability to commit crimes against the citizens of Republic City. The criminal attempted to escape, only to be defeated by Avatar Aang who removed Yakone's bending.
In 128 ASC, a Republic City underground malefactor named Yakone was tried for his criminal acts upon the city and its citizens. He had apparently been accused on multiple accounts, but was cleared each time. Avatar Aang and Chief Toph Beifong had been trying to convict Yakone for years, but due to the apparent impossibility of his crime - bloodbending without the presence of a full moon - they were unsuccessful. Five years before the birth of his son Tarrlock, Yakone was tried once more, this time with dozens of witnesses. The testimony showed that there was enough evidence from apparent victims to lock Yakone away, but the jurors were unsure due to the fact that all of Yakone's crimes were on dates on which there was no full moon.
The verdict was finally delivered by Councilman Sokka who was the chairman and the Southern Water Tribe representative during that time. He and the other council members decided that it was possible to bloodbend without the presence of a full moon, using his own life experiences, such as Toph inventing metalbending and the rare abilities of Combustion Man, as justification. Yakone was sentenced to life in prison for his crimes. Before he could be detained, however, Yakone demonstrated his powerful skills and subdued every person in the courtroom, including Avatar Aang. He used his skills to draw Toph over and unlock his handcuffs, prompting his escape after knocking the viewers out cold. He fled city hall on a horse-drawn carriage, only for Aang to recover and chase him down, breaking his carriage with airbending. Yakone tried to bloodbend Aang to death, but the latter's Avatar State was activated, enabling him to trap Yakone. The Avatar then removed Yakone's bending abilities.