Burden and Standard of Proof

A man has been charged with murder following the death of his wife during an argument at their home. The prosecution evidence establishes that the defendant struck his wife with a heavy ornament, causing fatal head injuries. The defendant claims the ornament slipped from his grasp accidentally as he gestured during the argument. The trial judge tells the jury that the prosecution has proved the killing, and it is now for the defendant to prove the killing was accidental.