Who suspects Macbeth of the murders?

In Act 3, Scene 1 of the play "Macbeth," written by William Shakespeare, Banquo becomes suspicious that Macbeth is responsible for Duncan's murder. During this scene, Macbeth becomes fearful of Banquo's suspicions.

Macbeth spend a majority of this scene thinking about and planning the murder of Banquo, including talking to the men that he wished to commit the murder in secret. "Macbeth" is a play that focuses on the how the human experience is affected by committing sin, such as murder. The sins that Macbeth commits throughout the play cause him to become fearful of his dearest friends, such as Banquo.