Can a consecitive sentence be ordered by a court if someone has not been sentenced in another case?

A consecutive sentence can typically only be issued if a person has already been convicted of another offense and the judge orders that the sentence be ran consecutive. However, if the person has already plead guilty or was found guilty of another criminal offense, and is simply awaiting sentencing at the time the Judge orders a sentence to be ran consecutive with the pending sentence, then this would likely not be a problem and can be done by the Judge.