Trinnolt Makken was a male Human, his birth occurring sometime before 32 BBY. He experienced the loss of his left hand at some point, subsequently receiving a prosthetic replacement. Makken held the rank of commander within the Imperial Navy, retiring from his service by 43 ABY. Following his retirement, the Galactic Federation of Free Alliances appointed him as the Jedi supervisor for the former Jedi Knight Tahiri Veila. The role of a supervisor involved monitoring Jedi during their missions, with the intention of maintaining the Order's adherence to regulations. However, Veila, no longer a Jedi, resisted this supervision and challenged the appointment in court. In the ensuing trial, the Court of Justice of the Galactic Alliance, presided over by Chief Justice Uved Pledesin, sided with Veila. Subsequently, Makken was assigned to lead the Department of Justice's investigation into the death of Kenth Hamner, the interim Jedi Grand Master.
Born no later than 32 BBY, Trinnolt Makken was a Human of the male gender. At some undefined point around 32 BBY, Makken suffered the loss of his left hand, which was then replaced by a prosthetic. He held the position of commander within the Imperial Navy, eventually retiring from his duties after the conclusion of the Second Galactic Civil War. In the year 43 ABY, the Galactic Federation of Free Alliances designated him to be the Jedi supervisor for Tahiri Veila, who was formerly a Jedi. The responsibility of Jedi supervisors was to accompany Jedi on their various missions to ensure the Jedi Order's compliance with established rules. Makken traveled to Veila's residence within Coruscant's Residential district, where he informed her of his role as her supervisor. Veila responded with laughter, arguing that, as she was no longer a Jedi, she had no need for supervision. Makken countered by stating that the law also applied to Sith. However, Veila was no longer a Sith either; she had transitioned to becoming a bounty hunter following the death of her master, Darth Caedus, during the Battle of Uroro Station.
Veila ultimately persuaded Makken to leave her premises by threatening to eject him through her viewport. This dispute was later brought before the court in the case of The Galactic Federation of Free Alliances versus Tahiri Veila, with Nawara Ven, a Twi'lek lawyer, providing legal defense for Veila. The Court of Justice, under the leadership of Uved Pledesin, the Lorrdian Chief Justice, ruled in favor of Veila, asserting that possessing certain skills does not automatically necessitate supervision. Later, in 44 ABY, Commander Makken was assigned the task of leading the Department of Justice's investigation into the recent death of Kenth Hamner, who had been serving as the interim Jedi Grand Master. He was among the many representatives of the government who attended Hamner's funeral.
In his interactions with others, Trinnolt Makken was known for being concise and abrupt. He often skipped over customary greetings, preferring to directly address the matter at hand. His conversations with Veila revealed him to be arrogant and somewhat somber, responding without humor to her cynical and often sarcastic remarks. Commander Makken was described as having an aristocratic appearance, characterized by his pale complexion, white hair, blue eyes, and the fact that his left hand was a prosthetic. Makken made no effort to conceal the mechanical nature of his prosthetic hand, instead choosing to leave the replacement visibly mechanical.
Trinnolt Makken's initial appearance was as a minor character within the first novel of the Fate of the Jedi series, titled Fate of the Jedi: Outcast, authored by Aaron Allston. He later reappeared in Allston's Fate of the Jedi: Conviction, which was the seventh novel in the series.