Order and disorder
The symbols that define the plot of the story show a dilemma between order and disorder. Although the dead plantation owner symbolizes order, he symbolizes a broken kind of order with no representation for anyone but the powerful. Therefore, the disenfranchised community that has been oppressed seizes the chaos of the moment to organize. The Gathering is an organized demonstration that if killing the plantation owner was a crime, they all want credit for it. They want a new order.
Age and time
The men are all old, and the man who is blamed is young. They want to steal his guilt because they are close to death anyway, but the Sheriff wants to take life away from them. This use of age shows that time on earth is limited, and in light of the difficulty of their life as chronically overworked, disenfranchised workers with no rights, their relationship to time is different. They are all of them ready to die for a crime they didn't even commit. They experience a shared frustration about time, because their lives were stolen from them.
Community and oppression
The imagery of community is shown most clearly under the pressure of true oppression and injustice. When the Sheriff comes to start taking people away to jail (and probably death), the community has its full expression. The whole community literally stands together in opposition of this unfair practice of law, and their actions clarify the injustice of the Sheriff's practice of law; he must use his suspicions and prejudice to seek justice, but that's no hindrance to him—that's how he was going to do it anyway.
Death and injustice
The symbolic imagery of injustice is death. This is clear from the places were death occurs in the plot. The imagery that defines the injustice of slavery is the death of the plantation owner. The community's response to injustice is to willingly accept the death penalty that would be the murderer's fate. Mathu faces death by accepting guilt for a crime he didn't commit. When Charlie comes forward to accept death on Mathu's behalf, as a Christ figure in the narrative, they simple murder him in cold blood and continue trying Mathu for the same crime. No justice is given when the white men kill an innocent black man, but intense pursuits of justice are given for the slave owner's death.
