Surely, if Miss Emily's house had ever been searched and the body of Homer Barron found before she died, she most likely would have been convicted of some type of murder. Assuming that Homer died of the rat poison, it could have been determined by a medical examiner of the period. There is the possibility that the deed could have been covered up by a friendly or sympathetic law enforcement official, but Miss Emily's time for special treatment had long since passed. It is also possible that a good attorney could have succeeded with some sort of defense due to insanity, although it seems clear that Emily's plan was well thought out in advance.
Concerning your question about Faulkner's "A Rose for Emily," first, as you word it, if she were "convicted," then of course she would be found guilty. That's the definition of convicted.
I'll assume you mean if she were put on trial, and answer accordingly.
The evidence certainly suggests Emily is guilty of premeditated murder. She buys rat poison, has a body/skeleton in a bed in her home, and leaves a hair in an indentation on a pillow beside the body. For a reader, this is certainly enough to convince one that she is guilty of premeditated murder.
Beyond that, whatever might happen in a court of law is speculation. In Emily's day, the law certainly could not prove Homer was murdered with the same poison that Emily bought. The law might also have a little trouble proving that Emily murdered Homer and not her servant--especially since he disappears out the back door right after Emily's death. Who knows, the law may not even be able to prove Homer was murdered at all, or even that the skeleton is Homer's.
If the person wasn't murdered, or if the servant murdered him, then Emily is only guilty of necrophilia.
Those are just some of my speculative thoughts on convicting Emily. I wouldn't take them too seriously.
I think you must mean if she were to be charged, because if she's convicted, she's been found guilty.
I would think that Miss Emily might have a chance of being found not guilty of murdering Homer Barron. At least, I think she would have a chance if the trial were held in that town and she was able to get a good lawyer.
I would think that she could get off by pleading insanity. She could say that she was made crazy by the way her father kept all the men away. She could say she was worried she'd never find a man and so when Homer rejected her, she went crazy.
I think she could get off because A) she was from a prominent family, B) Homer was an outsider and no one would miss him much and C) back in those days women were believed to be kind of unstable and overly emotional so the jury might buy her story.
I think that based on the facts presented that if Miss Emily had been found out back when Homer had recently died, she would have been charged with pre-mediated murder, charged, and been found guilty. People in the town were witnesses to her relationship with Homer as well as her desire to marry him. It is not so unusual for a prson who is rejected by a lover to take action by killing them. It is seen all the time through the criminal courts.
Miss Emily had been quite calm and demanding when she obtained the rat poision that she used to kill Homer. She did not particularly try to hide it. She has her own opinion based on ehr personal demands that she is above the law. Having this self-impression, killing Homer would ot be that much of a misdeed for her.