Answer:
R.W. and Melvin Simms
Explanation:
Roll of Thunder, Hear My Cry is a novel written by Mildred D. Taylor.
We follow the story of the Logan family (African Americans) and how they fought racism in Mississipi in the 1920s and later.
The mentioned robbery took place in the store whose owner was Mr. Barnett. Two white boys, R.W. and Melvin made T.J. Avery, an African American boy, to accompany them in the robbery. But, he was not okay with it. Boys stole the gun and attacked Mr. Barnett. After that, T.J. threatened to tell the police about this, so they beat him up.
When he somehow got home, a wild mass of white people appeared and they bullied his family, among that mass were R.W. and Melvin, who in order to cover their own misbehavior, attacked the boy and his family too.
In the end, T.J. ended up in prison with a death sentence.
