The man is accused of murdering the 10-year old boy referred to only as Bobby. The boy's mother is also accused. They were convicted in a lower court of manslaughter. The prosecutor says they should have been convicted of murder.
The man's defence lawyer Anders Berggren asked the man how he would react if somebody claimed he was a psychopath:
"I'm not the right person to answer that. But I don't think I am," he said.
Bobby was taken out of school on sick leave for the final month of his life last December, after bruises appeared round his eyes, the man told prosecutors.
Prosecutor Erik Handmark said that this was new evidence. In the lower court it had been claimed that he missed school due to a cold.
The man now says that the mother had made up the story of a cold when she told the school he would be absent.
"He looked awful with these black eyes," he said, claiming that Bobby had fallen down the stairs in their isolated house in Småland.
The man also claimed that it was the mother who was violent towards Bobby. He said she sometimes tied him to a chair and hit him with objects.
"She went black in her eyes, you couldn't contact her," he said.
When the couple found Bobby dead one night in January they didn't tell anyone. They left his body in his bedroom for a whole day, while they sat in the kitchen smoking and drinking. The next day they moved his body to a barn. they later dumped it in a lake.
Asked why they didn't raise the alarm, the man replied: "We'd read about parents who come under suspicion for beating their children to death."
Bobby had so many bruises on his body that they did not dare call anyone. But the man maintained that the bruises were due to accidents.
"But that doesn't make it look any better," he said.
"I was afraid - what would people think? And what I was afraid of is exactly what has happened, and why I am sitting here."
Berggren asked the man whether he has sadistic fantasies about other people.
"Are you talking about sex," he asked after a pause.
"No, about violence."
"I have never had that kind of fantasy outside a sexual context," he replied.