RIO DE JANEIRO, Brazil (AP) _ A judge sentenced a former police officer to 72 years in prison Thursday for his part in a 1993 massacre that left 21 residents of a Rio slum dead, court officials said.

Adilson Saraiva da Hora was one of 52 officers accused of taking part in a police death squad that invaded the Vigario Geral slum and began firing at random on the night of Aug. 29, 1993.

Investigators said the group was seeking to avenge the killings of four state policemen by drug traffickers from the slum a day earlier.

Despite the 72 year sentence, Hora should spend significantly less time in prison. Under Brazilian law no one can serve more than 30 years in jail and convicts become eligible for parole after serving a third of there sentences.

Hora was the fourth officer accused in the massacre to be convicted. Thirteen others have been acquitted.

Hora's lawyer Jose Vicente Alves said he would appeal the sentence.