The alarm came at 12 noon on Friday, the police said on their website.
A perpetrator assaulted a woman and, in connection with that, also assaulted a man near the home, says Mats Eriksson at the Stockholm Police.
The woman is seriously injured and has been taken to hospital by air ambulance, the man is slightly injured.
The perpetrator was found injured in a room a short distance away, says Eriksson.
After life-saving measures, he was pronounced dead. We believe he inflicted the injuries on himself.
The police are not looking for any more perpetrators and consider the incident to be isolated. It is suspected that those involved knew each other beforehand.
