Since Breivik has confessed to the July 22 attacks -- claiming they were necessary to protect Norway from being taken over by Muslims -- the key issue that remains unresolved is his mental health.
Those who survived the shooting massacre are bracing for the horror to return during the trial.
"I do not know how I will react, I do not think you can prepare for it," said Stine Renate Haaheim, a 27-year-old Labor Party lawmaker who survived the Utoya massacre by swimming away from the island.
Haaheim said she is concerned that Breivik will use the intense media focus during the trial to draw attention to his extremist views. Although she is curious about what snapped inside Breivik to turn him into a mass killer, she said "I don't think it will give any meaning to what has happened."