It was on September 15 that a shooting broke out in the district Ryd in Linköping.
A man in his 20s was taken to hospital with gunshot wounds.
Two men are already in custody on suspicion of involvement in the incident, which is classified as an attempted murder.
During the day, prosecutor Emma Högström requested another man arrested on suspicion of involvement in the incident.
It is about a man in his 25s, a resident of Linköping.
According to public documents, the man has not been convicted of a more serious crime before.