In what terrible way does Macbeth deal with Macduff, one of the noblemen at the court who was suspicious of Macbeth from the beginning?

In Act 3 of Macbeth, Macbeth is crowned
King of Scotland and after his coronation, he holds a banquet in honor of his new title. 
However, two men are missing from the banquet:  Banquo (Macbeth has had him murdered) and
Macduff, who has returned to his home in Fife, refusing to attend Macbeth's coronation.  Macbeth
is angered by Macduff's disrespect, and Macbeth's negative feelings towards the Thane suggest
that he thinks Macduff might be suspicious of him.  When Macbeth later learns that Macduff has
gone to England to see Malcolm, he plans to have Macduff's castle sacked and his entire family
and court murdered.  This is the terrible way in which Macbeth deals with Macduff--even at the
end of the play, Macbeth hesitates to kill Macduff because he says that he has the blood of
Macduff's entire family on his sword.