The attorney representing Randall Dale Adams--whose conviction in the the killing of a policeman was questioned by the Erroll Morris documentary film "The Thin Blue Line"--is scheduled to present a motion for a new trial in the Texas state court of appeals today. Adams was convicted nine years ago of the 1976 murder of Dallas police officer Robert Wood and was sentenced to death for the slaying. His sentence later was commuted to life in prison. "The Thin Blue Line" suggests that police and prosecutors suppressed evidence that disproved Adams' guilt and used five questionable witnesses. Adams' attorney, Randy Schaffer, contends that Adams did not receive a fair trial, largely because prosecutors did not turn over documents favorable to the defense.