An Ogdensburg man already a prisoner at the St. Lawrence County jail faces additional charges for allegedly assaulting another inmate.

Sheriff's deputies say the other inmate was injured after 24 year old Robert Middlemiss of Ogdensburg allegedly assaulted him on July 8.   Middlemiss was charged with second degree assault, arraigned in Canton town court, and returned to jail on $2,000 bail.   He was in jail already on $10,000 bail in connection with an alleged domestic dispute in late May.   See our story on the earlier charges.