The police still haven't found the second gunman who was reported by some witnesses. So far only 2 weapons were discovered on Utøya, both in possession of Anders.
One hand gun, and one automatic rifle.
So far, there is no evidence any other weapon was used.
There is no evidence of knife being used.
All victims were shot at close range.
So far, Anders claims he was alone and majority of
witnesses who survived have only seen and identified him as shooter.
Other then reports by a very few witnesses, police have no any other tangible evidence of the second gunman.
If the police discovers any other evidence of the second gunman, sure it will be all over the world news.
Anders came to Utøya by ferry, alone.
The second person was arrested in Sundwoll (not on Utøya island) because he was wearing a knife.
As police was unable to find any evidence of him being on Utøya, or him handling fire arms, he was let go.
He said he was wearing a knife for his own protection, after he heard about bomb and then shooting on the Utøya island.
He was let go short time after the arrest.
Many people were arrested in Norway since bombing, but all were let go. Just usual police work, they are investigating all possible leads and all tips from public.
Police received thousands of tips.
Several times parts of Oslo were closed because police was investigating suspicious objects, objects that could have been a bomb.
People were paranoid one day after the blast, and called police for a half empty plastic garbage bag left on a street corner.