"My client admits some responsibilty, at least for aggravated assault and manslaughter. That basically means he admits to having been involved in events that have led to the girl's death," the man's lawyer Anton Strand told daily Dagens Nyheter (DN) on Tuesday.
Martin Cullberg, the lawyer of the younger brother, had maintained on Monday that his client denied the crime, leading to the 28-year-old's release during the evening. However, he is now suspected of protecting a criminal.
The two brothers, neighbours of the murdered girl, were both initially arrested shortly after the girl was found dead inside a block of flats.
The older brother had to be treated in hospital after jumping from a window on the third floor of the apartment to escape police making arrests.
Prosecutor Ewa Tvengström, leading the murder investigation, explained at the time of the arrests that the man's injuries at first prevented a speedy investigation.
But on Tuesday the 31-year-old was remanded into custody by the Attunda District Court under suspicion of murder.
Tvengström couldn't say why the 31-year-old had attacked his young neighbour.
"But we have an idea what lead up to the event," she told news agency TT.