One citizen of Maycomb that author Harper Lee uses to build suspense in To Kill a Mockingbird is Miss Stephanie Crawford.
It is through Miss Stephanie Crawford's gossip that we learn of rumors and myths surrounding Arthur (Boo) Radley. For instance, it's through Miss Stephanie that the children learn Arthur had spent time with a rowdy crowd of boys as a young teenager. Upon arrest, all the boys but Arthur had been sent to the state industrial school to receive excellent educations; however, Arthur's father had considered the school to be a disgrace and kept him under house arrest. The children further learn through Miss Stephanie the rumor that, after having served many years under house arrest, Arthur had stabbed his father in the leg with scissors. Finally, the children learn from Miss Stephanie the myth that Arthur only comes out at night "when it's pitch dark," and she had woken up in the middle of the night once to find Arthur "looking straight through the window at her" (Ch. 1). According to Jem, Miss Stephanie described Arthur's head as looking "like a skull" (Ch. 1).
A second citizen Harper Lee uses to create suspense is Bob Ewell. Atticus reveals through his cross-examinations of Mayella and Bob Ewell that Bob is a drunkard who is guilty of physical abuse. The day after the trial, Miss Stephanie informs the children that Bob had "stopped Atticus on the post office corner, spat in his face, and told him he'd get him if it took the rest of his life" (Ch. 22). While Atticus doesn't take the threat seriously, Aunt Alexandra and the children do, fearing for Atticus's safety. Hence, not only do Bob's actions create suspense, but also Aunt Alexandra's and the children's fears help feed the suspense. Little do they know that Bob will try to fulfill his threat by attempting to kill Atticus's children.