“The man allegedly told the 19-year-old that ‘if you don’t sleep with me I will tell everyone you did anyway’,” said prosecutor Catharina Kjelsson to daily Aftonbladet.
Hans Wikman, 84, was found dead in his flat in Sundsvall, northern Sweden, at the end of November last year.
After having been fatally stabbed in the back he had been dragged into the bathroom and left there under a heap of towels and clothes.
Quite soon in the investigation, police turned their attention toward a 19-year-old high school student.
However, investigators were unwilling to disclose the exact nature of the relationship between the deceased man and the suspect.
When he was initially arrested, the 19-year-old denied all allegations, but suddenly made a blistering u-turn in January and requested a meeting with the police.
Under interrogation, the 19-year-old then went on to admit responsibility for the crime but claimed that it was motivated by the fact that the 84-year-old had tried to blackmail him into performing sexual favours.
“He says the man made sexual advances toward him,” said Kjelsson to the paper.
She also said that police found evidence that ‘partly’ substantiated the teenager’s claims.
Formal charges were filed against the 19-year-old on Friday.
The murder weapon has still not been found, although the young man has led the police to where he allegedly dumped it in the local Selångerån river.
Police will be holding a press conference regarding the case on Friday afternoon.