He has since been acquitted in three cases, and had the charges dropped in the remaining five.
However, it was unclear if the retrials would lead to Bergwall being released from the Saeter psychiatric clinic, 190 kilometres (120 miles) northwest of Stockholm.
He’s been a patient at the institution since being convicted of armed robbery in 1991, three years before admitting to his first murder.
“The care he receives is based on an earlier ruling, which will determine whether he will (continue) to receive care or not,” Ulf Christofferson, head of operations at the clinic, told the tabloid Expressen.
“It’s the same regardless of the acquittal,” he added.
Bergwall said he would launch legal proceedings against the clinic.
“I now move on. But first, today’s decision has to sink in and then it’s time for the next process, that against Saeter,” he wrote on his blog.
A number of high-ranking opposition politicians and legal experts have called for an independent commission to examine how Swedish courts could convict Bergwall based on so little evidence.
In response, Justice Minister Beatrice Ask announced a review in August 2012.