International Standard Version "Every murderer of a human being is to be executed only according to testimony given by multiple witnesses. A single witness is not to result in a death sentence.
American Standard Version Whoso killeth any person, the murderer shall be slain at the mouth of witnesses: but one witness shall not testify against any person that he die.
Young's Literal Translation whoso smiteth a person, by the mouth of witnesses doth one slay the murderer; and one witness doth not testify against a person -- to die.