The 38-year-old man was arrested last summer on suspicions of murdering Johansson, who was reported missing in August 2010.
After the trial concluded about two weeks ago, the man was released to await a verdict, an indication that the evidence against him might not be sufficient to secure a conviction.
In a ruling issued on Friday, the Uddevalla District Court found there wasn’t enough forensic evidence or testimony tying the man to the alleged murder.
The court also describes the prosecution’s case as more of a “scenario that describes what could have happened” and that prosecutors failed to prove Johansson’s disappearance could be explained in some other way.
Johansson was reported missing by her mother on August 2nd last year and two days later her ex-boyfriend was arrested on suspicion of her murder despite the fact that police found nothing incriminating in her house.
It was not until friends of Johansson moved into the house five months later that blood stains were discovered on a mattress, which had been covered by a snug-fitting blanket.
Further examination inside the house revealed what police suspect to be a bullet hole with bone fragments on a wall next to the bed.
However, Johansson’s body has never been found, nor has a murder weapon ever been recovered.
“I’m surprised over what the court write in their conclusions,” prosecutor Per-Åke Kvarnström told news agency TT.
“That an unknown man could’ve murdered the woman and disposed of the body, and that the ex-partner later arrived and covered up the traces. Why would he do that?”
Kvarnström argued that he has put it beyond reasonable doubt that Johansson’s 38-year-old ex-boyfriend committed murder, but that in its ruling, the court mentions unreasonable doubt.
The court was also sceptical about the fact that only some of the blood from the victim’s bed was analyzed.
“That’s a concern we’ll be able to get rid of in the court of appeals. The police took several samples where were sent to SKL (Swedish National Laboratory of Forensic Science). SKL is currently analysing the others,” said Kvarnström.
“We’re going to show that all the blood comes from the woman.”
Kvarnström said he plans on appealing the verdict next week.
Johansson’s ex-boyfriend has continually denied committing any crime.