“My client says he is innocent,” Rönnbäck told the newspaper.
Rönnbäck also insisted that she intends to call additional witnesses to testify at the Court of Appeal.
Skaraborg District Court handed 35-year-old Nerijus Bilevicius a life sentence on November 17th.
Lisa Holm's death is one of the most high profile in Sweden this year. She was killed after she went missing in June following a shift at a cafe in Blomberg near Lidköping in western Sweden.
Although an autopsy found that the teenager had not been sexually assaulted, she was partially unclothed when she was found and her mouth had been taped shut.
The verdict said that Holm was killed on June 7th in a barn in Blomberg, after which she was taken to the place her body was found a few kilometres from the area.
It said forensic evidence including traces of Bilevicius' DNA strongly indicated that he was guilty. It also noted that he lacked an alibi for the time of the murder.
"If there had been [DNA] traces on an item of clothing, that could have been accepted. But there are so many traces, both on the scene of the crime and where the body was found," the court's chairwoman Anna-Karin Lundberg told the TT news agency after the verdict was pronounced.