What is a dramatic Irony in to kill a mockingbird

I think that the reader knows that Tom Robinson doesn't have a chance at being aquitted for the rape of Mayella Ewell. There is some suspense about the outcome but most readers will know a black man's word against a white woman, in this era and setting, will never be heard.

In Chapter 8 Boo gives Scout a blanket while Miss. Maudie's house burns. Most readers can interpret that Boo Radley gave it to her.