How many people did Richard III kill in Shakespeare's Richard III?

He killed 12 people, though he did not literally act out all 12 murders. He kills off Prince Edward, King Henry VI, King Edward the IV, Clarence, Lady Anne, Rivers, Gray, the 2 young princes, Hastings, Vaughan, and his right hand man: Buckingham. Richard hires people to act out the murders so that he can disassociate himself with villainous behavior.