Macbeth and his wife plan to blame the guards for killing the King. Indeed, after the murder, Macbeth slays them both claiming that they had commited the deed. Almost immediately, however, the sons of Duncan (Malcolm and Donalbain) decide to flee since they fear that they will be suspected of either killing their father or hiring the killer. Later, it is discussed that they are suspects, but it is also made clear that most people recognize that it's really Macbeth who has done it.
There are many answers to this question.
Macbeth
Witches
All three of these can be supported with textual evidence.
Macbeth believes he has to kill Duncan's guards in case they heard anything happen in the room while Macbeth was killing Duncan.
The king
Duncan is his cousin. Duncan is his king. Duncan is his guest. If he murders Duncan, he invites others to murder him. Many people like Duncan for being a nice guy and will be angry when he is killed.
killing king duncan (:
He had his suspicions because the fact the Macbeth killed the servants he blamed the murder on.
They were killed by Macbeth because he blamed them for Duncan's murder.
Killing Mr. Griffin by Lois Duncan was published in April 1978.
Macbeth believes he has to kill Duncan's guards in case they heard anything happen in the room while Macbeth was killing Duncan.
The king
yes
Lady Macbeth is blamed for bribing the grooms to kill Duncan in William Shakespeare's play "Macbeth." She drugs their drinks to frame them for the murder.
Duncan is his cousin. Duncan is his king. Duncan is his guest. If he murders Duncan, he invites others to murder him. Many people like Duncan for being a nice guy and will be angry when he is killed.
Killing him in his sleep. Scandalous!
She talks her husband into killing Duncan.
killing king duncan (:
Gavrilo Princip a Serbian Student
King Duncan was murdered by Macbeth in order to take the throne for himself.