FORT WORTH, Texas — Sitting in the leather swivel chair normally occupied by the judge whose future involvement in a case she will determine, a former state appellate court justice heard again and again Thursday about matters of demeanor, fairness and vacation calendars. On a bench ledge below Retired Second Court of Appeals Justice Lee Gabriel is the nameplate of the state district judge who defense attorneys in the murder case are seeking to recuse. “Hon. David Hagerman,” it reads. Gabriel will determine whether grounds exist to keep the Aaron Dean case under the dominion of Hagerman or assi…