It is still very unclear after the events at the high school in Malmö on Monday.
At 23.36, the man is arrested on suspicion of murder.
There is currently no motive for the act and the police investigation is in full swing.
- We will work with interrogations with both school staff and others, if there are private relationships or the like.
A large number of people will be heard during the day and next week, says Petra Stenkula, police area manager in Malmö.
See a summary of what happened on Monday in the video above.