Those of his chamber, as it seem’d, had done ‘t:
Their hands and faces were an badged with blood;
So were their daggers, which unwiped we found
Upon their pillows:
They stared, and were distracted; no man’s life
Was to be trusted with them.
– William Shakespeare
Macbeth, Act 2, Scene 3. Lennox reveals how it looks as if Duncan’s guards were not trustworthy and killed him. They were covered with blood and the daggers were on their pillows. Just like Lady Macbeth meticulously planned it. How appearances can be deceptive.