He has been convicted of killing two, and attempting to kill five others, as well as two counts of making illegal threats.
The court says that his crimes were characterised by "extreme ruthlessness, and a lack of empathy." Judge Lennart Strinäs says that there was no possibility of Mangs getting a shorter sentence.
His sentencing was delayed by an investigation into his mental health, and then by accusations that one of the judges had a conflict of interest.
The killer will also have to pay damages to his victims, of 1,175,000 SEK.