Details about the murder weapon, about the woman's injuries and a couple of car keys at the crime scene. In conversation with the police undercover officer, the 35-year-old suspect told details about the murder, which only a perpetrator should know about.

But despite this, he was acquitted by Växjö District Court on Monday.

The reason is that the man has provided a large amount of information that has been contradictory – sometimes it has been true and sometimes not. His story may also have been coloured over the years, when he has been interrogated several times and also sought information about the case on various forums.

"Guessing and speculating"

Chief Judge Daniel Haraldsson explains how the district court reasoned in an email to SVT:

Regarding the infiltration, the defendant has stated that he has been trying for several years to understand what happened to his mother. He has said that he has filled in in his thoughts the facts he has received with various theories. He has also stated in the conversations that he is guessing and speculating. In some respects, it also appears that this is what he is doing.

An example of details that the district court weighed into the assessment is the son's information about where the axe was found at the murder scene.

See more in the clip above – and hear SVT's reporter explain the evidence.

Will be appealed

There is no forensic evidence linking the man to the crime and the information obtained by the undercover agent is not sufficient to rule out that someone else committed the crime, according to the district court.

It was in March 2011 that a 58-year-old woman was found murdered in her garage. One of her sons was already the prime suspect at the time, but was released due to lack of evidence.

Twelve years later, charges were brought against the same son, after new evidence was presented – an undercover agent from NOA, the police's national operations department, had managed to obtain information by becoming "friends" with the man. It is a method that is considered controversial, as evidence is provoked.

The son has always denied any wrongdoing. Prosecutor Emma Berge told SVT that the District Court verdict will be appealed.

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Watch the summary of the murder investigation in the clip. Photo: Police preliminary investigation