SAO PAULO - Fifteen Brazilian police officers were found guilty on Wednesday of killing four inmates during a 1992 riot at Sao Paulo's Carandiru prison.
Each was sentenced to 48 years in prison, although no one can serve more than 30 years under Brazilian law.
It was the fourth and last trial involving what has been dubbed the Carandiru massacre, in which 111 prisoners died at the since-closed prison.
In April of last year, 23 officers were found guilty of killing 13 inmates and sentenced to prison terms of 156 years each.
Four months later, 25 officers were convicted of killing 52 prisoners. They were sentenced to 624 years.
Earlier this year, 10 officers were sentenced to more than 90 years for the shooting deaths of eight inmates.
In 2001, police Colonel Ubiratan Guimaraes was sentenced to 632 years in prison for using excessive force when he ordered police to quell the rebellion.
However, a Sao Paulo state appeals court overturned the conviction in 2006 based on arguments that Guimaraes was following orders.
Guimaraes was found dead in his Sao Paulo apartment seven months later with a gunshot wound to the chest. His girlfriend was tried on homicide charges and later acquitted.
The riot began with a brawl between rival groups of inmates and mushroomed into an uprising that quickly spread through the penitentiary, which was built to hold fewer than 4,000 inmates but was housing nearly 8,000.
The riot raged for around three hours before more than 300 officers entered the facility, gunning down more than 100 inmates in about 30 minutes.
Autopsies found the dead were riddled with an average of five bullets. No police officers were killed in the incident.
The prison was torn down 10 years after the massacre and transformed into a park.