In 2370, she presided over Miles O'Brien's trial for smuggling weapons to the Maquis. In fact, Makbar was part of an elaborate scheme to attempt to discredit the Federation's policies and to establish grounds to invade the DMZ to eliminate the Maquis. They attempted to portray the Maquis as "savage, Federation-born killers" who were operating with secret but official sanction from Starfleet Command. The plot failed when Commander Sisko discovered that it was a Cardassian agent disguised as Raymond Boone who used O'Brien's recorded voice to steal the weapons from Deep Space 9. (DS9: "Tribunal")
"Mrs O'Brien, there's nothing for you to prepare. Your husband's verdict has already been determined. He is guilty. The trial will reveal how this guilt was proven by the most efficient criminal investigation system in the quadrant."
- - Makbar, to Keiko O'Brien
"His execution is scheduled for next week."
"How can you schedule an execution before the trial even begins?"
"We believe in swift justice."
- - Makbar and Keiko O'Brien
"The offender, Miles O'Brien, human, officer of the Federation Starfleet has been found guilty of aiding and abetting seditious acts against the state. The sentence is death. Let the trial begin."
- - Makbar, introducing Miles O'Brien's trial
"Gul Evek has tied the Maquis to this plot by quoting reliable sources. I think we deserve to know who these reliable sources are."
"Can you provide any details, Gul Evek?"
"I'm afraid that information cannot be revealed without risk to national security, Madame Archon."
"That's an acceptable answer."
- - Odo, Makbar and Evek
"Once again the Cardassian system of jurisprudence has worked to protect its people. A guilty man has been brought to justice. But, never let it be said that there is no room in this system for compassion. I sense in Mister O'Brien, a man with strong family ties, the potential for rehabilitation. And I'm sure he has gained a new appreciation of Cardassian law through this difficult process. Therefore, I am pleased, in the spirit of furthering Cardassian-Federation relations, to hereby set aside the verdict and to release Mister O'Brien into the custody of his Commander, Benjamin Sisko."
- - Makbar, after the plot to discredit the Federation is revealed
Makbar was played by actress Caroline Lagerfelt.
The final draft script for "Tribunal" gave the pronunciation of Makbar's name as "MOCK-bahr" and went on to describe her as simply "a Cardassian woman". 
The character was used to personify the cold, even grinding, philosophy of the Cardassian judicial system. In her hairstyle, hair department head Josée Normand incorporated some of the unique design details from the Cardassian courtroom. "It was one of those times that I went over to the set for inspiration," she said. (Star Trek: Deep Space Nine Companion, pp. 149 & 150)
Two of the costumes worn by Lagerfelt as Makbar were later sold off in the It's A Wrap! sale and auction. The first, a royal blue, velvet, long-sleeved, full-length jumpsuit, was sold for US$153.50  while the second, a long-sleeved, full-length blue and black patterned jumpsuit, was sold for US$410.65. 
In the Star Trek: Typhon Pact novel Raise the Dawn, set after the Dominion War, Makbar presides over the trial of Denison Morad, who has destroyed a Federation industrial replicator in Lakat. Makbar, a member of the True Way, is lenient towards Morad and sentences him to just one hundred days in the Hutet labor camp, with the intention of recruiting him into the group when he is released.
Makbar is also featured in the Star Trek Customizable Card Game.