(Dover, NH) - A Dover man faces arraignment after his arrest on a robbery charge.23 year old Gregory D. Castoras was charged with a Class A felony for the Tuesday morning incident in which a woman said she was robbed at knifepoint in the area of New York and Park Streets in Dover by an acquaintance named "Greg".   Police were able to identify Castoras as the suspect and issued an arrest warrant.  Rochester police arrested Castoras Wednesday afternoon and he is being held in the Strafford County Jail awaiting further court action.  The victim of the robbery was not injured.