How does the attitude of the people in town towards Emily work in her favor when she decides to commit a crime in "A Rose for Emily"?

Emily is so secretive and reclusive that people do not even realize she has killed someone because no one is allowed in the house.

Emily considers herself superior to her townspeople.  Her attitude is to avoid them and expect them to avoid her.  She is also very stubborn and eccentric, as evidenced by her refusal to pay taxes.  She insists on living off of the legacy of her also eccentric father, long after he is dead.  Emily is so odd that no one really questions anything she does.

When Emily’s beau Homer Barron disappears, no one thinks that she killed him and left his body in the house.  He is a “Yankee” and they just assume that he went back where he came from.  They know Emily is strange, but they never assume she is a murderer.  She seems so timid.  She has never been able to have a boyfriend, because when she was younger her father scared them all off.  They just assume that she will be a spinster.

So she vanquished them, horse and foot, just as she had vanquished their fathers thirty years before about the smell. That was two years after her father’s death and a short time after her sweetheart—the one we believed would marry her—had deserted her. 

Emily kept her boyfriend in her bed, and apparently was unaffected by the smell of his body rotting away.  The townspeople do not confront Emily or inspect the house.  They had enough trouble earlier getting her father’s body, and they knew he was dead!  So they settle on a solution.

Now and then we would see her at a window for a moment, as the men did that night when they sprinkled the lime, but for almost six months she did not appear on the streets.

The problem is solved, right?  There is no more bad smell!  It is not until Emily dies that they find Homer’s corpse, and realize she has been sleeping next to it.  Emily got away with the crime because no one wanted to cross her.  She was too stubborn and strange.  Her secretive nature meant that no one wanted to ask too many questions.  They just sneaked in and sprinkled lime to cover the smell!