It was the Eskilstuna courier who first reported that the man was arrested on Monday.
The 22-year-old is also suspected of attempted murder and aggravated weapon crime.
Prosecutor Anna Asklöf believes that the two detained men were at the scene at the same time as the shots were fired at the 14-year-old.
- We have received information from people in the investigation and who described this, says Anna Asklöf to SVT Nyheter Sörmland.
The investigation is now continuing with further questioning, door knocking and analysis of, among other things, mobile phones.
- We are working on.
Not everyone wants to talk to us in this type of investigation, says Anna Asklöf.