The two men and their families had gathered to have dinner together at one of their homes in Onsala, near Kungsbacka, in December. But when they were about to clear the table, the 40-year-old “suddenly, without warning” stabbed his friend in the chest with a kitchen knife, according to police interviews with the wives.

He then went to a neighbour's house and attacked a couple in their thirties with an axe and a knife. Both survived with permanent brain damage. The 40-year-old was soon arrested by police arriving at the scene.

A psychiatric investigation found that the man, who was 39 at the time, had been suffering from a persecution complex and had also suffered several psychoses.

It also found that there was a risk he would reoffend if freed.

Police on the street where the murder took place. Photo: Adam Ihse/TT

Varberg district court on Thursday sentenced him to psychiatric care in a closed facility for offenders. He also has to pay around 570,000 kronor ($68,817) in damages to the neighbours and 325,000 kronor to the murdered man's family.

The 40-year-old's lawyer, Leif Silbersky, had pleaded for a not-guilty verdict, arguing that the man was so mentally ill at the time that he had committed the murder and attempted murder without intent to kill.

“He's going to receive care even if he is not convicted,” Silbersky told regional newspaper Hallands Nyheter when the trial ended two weeks ago.

Onsala is a wealthy area 45 kilometres south of Gothenburg with more than 11,000 residents.