In To Kill a Mockingbird, Tom Robinson was a victim of a crime he did not commit. People accused him of raping a woman, when the woman was lying all along. Robinson was killed trying to escape prison. Emmett Till however, he was just a victim of senseless racism in the south and was killed for being black and talking to a white woman. That is one comparison.
Another comparison would be, the two stories both involve the south. There were many terrible things that happened to black people in the south not that long ago. These two stories show that very well. A difference between the two stories is that Tom Robinson had a trial