Memorial services were held Friday to mourn the victims of the bombing and youth camp shooting. An 18-year-old Muslim girl was the first victim to be laid to rest.
Sixty-eight of the victims were killed on an island and eight died after a car bomb exploded in downtown Oslo.
Anders Behring Breivik confessed to both attacks, but pleaded not guilty. He was picked up at jail on Friday and transported to Oslo for further questioning.
Investigators believe the 32-year-old acted alone and haven't found anything to support his claims that he's part of an anti-Muslim militant network plotting a series of attacks across Europe.
Police have charged Breivik with terrorism, which carries a maximum sentence of 21 years in prison. However, it's possible the charge will change during the investigation to crimes against humanity, which carries a 30-year prison term, Norway's top prosecutor Tor-Aksel Busch told The Associated Press.
The Associated Press contributed to this report.