Updated

Fifteen Brazilian police officers have been found guilty of killing four inmates during a 1992 riot at Sao Paulo's Carandiru prison.

On Wednesday, 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 now 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.