A Serbian court on Thursday convicted and sentenced to 20 years in prison a young man who gunned down nine people and wounded 12 in one of two back-to-back mass killings last year that shook the Balkan nation.

Uros Blazic, 21, took up an automatic rifle on May 4, 2023, and opened fire at multiple locations in the villages of Dubona and Malo Orasje, south of Belgrade, randomly shooting at young people hanging out on a spring evening.

Blazic was "aware of his actions and their illegality, and with relentless violent behaviour" killed and wounded people, judges said.

The mass killings in close proximity stunned the country, which was used to wars and crisis but where mass shootings were relatively rare. The tragedies later triggered a wave of street protests and a crackdown on widespread illegal gun ownership.

The 20-year prison sentence for Blazic is the maximum permitted under Serbian law for people under 21 years of age. Blazic was 20 when he committed the crime.

Separately, the gunman's father, Radisa Blazic was also convicted for illegal possession of guns used in the shooting and sentenced to 20 years in prison.

Admits to 'hideous acts'

During his trial, the younger Blazic said he could not explain what prompted him to kill so many people. He said during closing arguments that he had felt victimized but that there could be no justification for what he had done.

"I committed hideous acts, and I deserve the toughest punishment," he told the court. Serbian media have reported that Blazic, who had a police record, was known for violent outbursts and aggressive behaviour prior to the shootings.

Parents and relatives of the victims were present in the courtroom in Belgrade as the verdict was read out. Many of them sobbed as they entered the court on Thursday morning, wearing shirts with the images of Blazic's victims.

Blazic's carnage came just a day after a teenager using his father's gun shot and killed nine fellow students and a guard at an elementary school in central Belgrade in what was Serbia's first-ever school shooting.

The parents of the school shooting suspect have gone on trial in Belgrade. The suspect himself was below the age of criminal responsibility and remains in a specialized mental institution.