SARPONG v. THE REPUBLIC Criminal law and procedure—Close of prosecution’s case—Powers and duties of trial judge—Charge of fraud by false pretences—Failure of prosecution to call vital evidence to establish that representation allegedly made by accused false to his knowledge and made with intent to defraud—Legal duty of trial judge to rule that no prima facie case had been established against accused—Trial judge nevertheless inviting accused to open his defence—Effect of failure of trial to perform legal duty at close of prosecution’s case.