Tell Tale Heart

The first tool of characterization would be appearance. The old man's eye is a tool in itself. Through his eye, we can infer the man is sick.... it has its own persective, its own view. The old man doesn't see clearly, he sees in shadows, and yet, the eye seems to have a life of its own.... it seems to see things the old man does not.

Another tool would be Poe's uses of the narrator and actions. We can surmise what the narrator is like simply by experiencing his movements. He's sneaky, he gathers information by spying, he hatches plots, and commits murder. This characterization denotes him as dangerous and untrustworthy.... but we also see that he feels guilt in his confession.