Updated

A Swedish court has commuted the life sentence of a convicted mass murderer to a 33-year prison sentence, making him eligible for release in 2016.

The Stockholm District Court says Tommy Zethraeus, who was also found guilty of the attempted murder of five people in a 1994 shooting spree outside a nightclub, could be released once he has served two-thirds of his sentence — in line with Swedish custom.

Tuesday's court decision came after three appeals by Zethraeus to have his sentence commuted. It noted that any uncertainty about him returning to criminal activity was not sufficient to reject the latest appeal, following numerous evaluations of his behavior during his imprisonment.

The shooting rampage, in which 11 others were wounded, shocked Sweden, where mass killings are rare.