One of three innocent Bajorans executed on Terok Nor for an attack on Gul Dukat, whose identity Garak is given in the vision of Things Past.
Jillur Gueta is the third of the Bajorans, with Ishan Chaye and Timor Landi, put to death on Terok Nor for an attempted assassination they had nothing to do with. Their case is the subject of the Deep Space Nine episode Things Past.
Odo was the investigator. He let the three be condemned without properly testing the evidence, and when the real bombers were later identified it was too late to matter.
In the vision that traps Odo, Sisko, Dax and Garak years later, Garak is seen by everyone as Jillur. The tailor, used to being the cleverest Cardassian in the room, finds himself treated as a Bajoran labourer by his own people and takes a beating for it before the group is marched out to be shot.