The obvious first example lies in the fact that Emily eventually murders Homer, after attempting to court him unsuccessfully, as the readers infer from his actions that he is a homosexual. She uses the rat poison she requests from the pharmacist in order to pull off the deed.
However, a different example, and perhaps a more subtle one, lies in the verbal violence throughout the book. When Emily and others would gather around to watch Homer "cuss the negroes", Homer is giving us an example of verbal violence. He does not treat his workers with respect; rather, he uses them for their physical labor abilities, and cusses them when they begin to slack or tire.
Finally, the townspeople are offended by the smell of what we later discover to be a rotting, decaying body emanating from Emily's house. Rather than simply asking her to make her house smell better, they sneak over during the night and dump lyme around the basement to get rid of the stench. This is an example of passive aggressive violence, another type that is common in many of Faulkner's works.
The definition of violence is "physical force intended to hurt, damage, or kill something." In this sense, there is very little violence in "A Rose for Emily." Emily murders Homer Barron, but she does it with poison, which is not "physical force."
Readers might infer that Emily's father was a violent man, but he might have been merely intimidating. Faulkner writes, "We remembered all the young men her father had driven away." He might have dispelled the suitors with a mere look or with harsh words. If he brandished a riding crop or walking stick at them, which readers might envision when reading the description, that could be considered violence. In legal terms, a threat of violence is violence.
When Emily's father died, the townspeople were "about to resort to law and force" to get Emily to turn over the dead body, but at the last minute she complied so violence was not necessary.
When the aldermen come at night to spread lime around the property to get rid of the smell, they "broke open the cellar door" and spread lime there. Although this was a use of physical force, it was not with the intent to damage Miss Emily's property, but rather to help her do something she was not doing herself.
At the end of the story, the townspeople use force to break down the door of Emily's room, which no one but Emily had entered for forty years. Here Faulkner uses the word violence: "The violence of breaking down the door seemed to fill this room with pervading dust." Still, the violence wasn't really with an intent to damage, but with the intent to ultimately improve the situation.
Although Faulkner's story revolves around madness and murder, there is in fact very little violence in the story.