What was the judicial system like in the South in the 1930's?
The presence of embedded racial discrimination was a fact of life in the Southern judicial system of the 1930s. The reality was that the entire nation was immersed in economic challenge and turmoil. The issue of race had already been problematic in the South even prior to the economic challenge of the time period. On one hand, the passage of the 13th, 14th, and 15th Amendments after the Civil War was meant to equalize out unfairness of race on a legal level. Using states rights as its justification, the Southern states were able to enact a series of restrictive actions called Jim Crow Laws that were rooted in segregation on the basis of race. This became embedded in both Southern society and its legal system leading into the 1930s. With the economic challenges of the time period throughout the nation, racial discrimination was not an issue that was openly addressed and not one that invited itself to transformation. Due to this, the issue of racial unfairness embedded into both social and judicial systems presented itself as a reality of life in the 1930s South.
This is a pretty broad question, but since your last question was about To Kill A Mockingbird, I will answer this with regard to that book.
The judicial system in the South in the 1930s was (as in the book) heavily tilted against black people. On a formal level, blacks were treated equally by the legal system. The one exception to this was the fact that blacks were not allowed to serve on juries. The Tom Robinson trial might well have ended differently if there had been any black jurors.
Just as important, however, was the informal bias against blacks. More or less everyone who participated in the judicial system would have held racist views. This would lead to verdicts like the Robinson one where a black witness's story would not be believed if it contradicted that of a white witness.