The famous sleepwalking scene of course occurs in Act V scene 1, and in it Shakespeare is careful to make Lady Macbeth allude to all of Macbeth's crimes up until this point in the play, clearly admitting his and her own culpability. Of course, throughout her speech, she is normally depicted as desperately trying to wash her hands, attempting to clean the blood from them that still metaphorically remains as a symbol of her guilt for the violence she herself has perpetrated.
She thus makes reference to Duncan's death, saying "Yet who would have thought the old man to have had so much blood in him?" Likewise, the slaughter of the Macduff family is mentioned: "The Thane of Fife had a wife: where is she now?" Banquo's murder is also refered to: "I tell you again, Banquo's buried: he cannot come out on's grave." Lastly, the sound of the knocking at the gates after Duncan's murder is mentioned as well:
To bed, to bed: there's knocking at the gate. Come, come, come, come, give me your hand. What'd sone cannot be undone. To bed, to bed, to bed.
So, in one scene, through the speech of Lady Macbeth, Macbeth is linked definitively to all of the crimes that he has committed. At the same time, the way in which Lady Macbeth is haunted by her own involvement and what her husband has done is clearly demonstrated, giving the Doctor and the Gentlewoman proof enough of the devilry that has gone on.