A retired military officer has been convicted as the mastermind behind the 1990 killing of Guatemalan anthropologist Myrna Mack.

A court secretary reads the long-awaited sentence to a standing-room only courtroom. Foreign diplomats, human rights activists, members of the military and relatives of the defendants and the victim awaited anxiously to hear the court's decision in this high profile trial.

A three-judge panel convicted retired colonel Juan Valencia and sentenced him to a maximum 30 years in jail for ordering an army sergeant to kill Ms. Mack. Sgt. Noel Beteta was convicted in 1993 as the man who stabbed the anthropologist and human rights campaigner 27 times.

Two other military officers have been acquitted. Human rights advocates are applauding the ruling, which marks the first time a high ranking military officer has been convicted for a human rights violation committed during Guatemala's 36-year civil war. The war ended in a 1996 peace accord.

At the time of her death, Ms. Mack had been conducting politically sensitive research on Maya Indians who had been internally displaced as a result of the war.

Valencia maintains that he is innocent and plans to appeal the ruling.