"It is based on information that has emerged in connection with the investigation of the incident at the school and has led to a new preliminary investigation regarding the new crime", writes prosecutor Kajsa Lindberg in an email to TT.
On Wednesday, the boy was remanded in custody for two weeks for attempted murder and for the new suspicion of preparation for murder.
We need to continue working on that part as well, the investigation can be disrupted by the suspect being at large, says Kajsa Lindberg after the detention hearing.
According to the suspicions in the detention application, the murder preparations took place between September 1 and 4 at an unknown location in Stockholm County.
The boy is already suspected of having shot a peer at Trångsundsskolan south of Stockholm on September 4. The shooting occurred in a confined space where no one else was present except those involved.
The 15-year-old was arrested the same day and has since been detained. The boy who was shot recovered without permanent injuries.
