OSLO, Norway -- Even if found criminally insane, confessed mass killer Anders Behring Breivik is likely to remain inside the walls of the prison where he has been held since his bomb and gun attacks in July.

Norway's Health Directorate on Wednesday approved plans to build a psychiatric ward inside Oslo's Ila Prison, specially designed for the 33-year-old right-wing extremist.

Breivik has been held at the prison since the twin attacks on July 22: a bombing in downtown Oslo and a shooting massacre at a youth camp outside the capital. The self-styled anti-Muslim militant admitted both attacks, which killed 77 people.

Since his guilt is not in question, Breivik's mental state was the key issue during his trial, which ended last week. The court is set to make a ruling on Aug. 24.

Earlier on HuffPost:

The Charges
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Anders Behring Breivik, a right-wing extremist who confessed to a bombing and mass shooting that killed 77 people on July 22, 2011, arrives for a detention hearing at a court in Oslo, Norway, Monday, Feb. 6, 2012. (AP Photo/Heiko Junge, Scanpix Norway)

Breivik is charged with terrorism and premeditated murder for a bombing in Oslo's government district, killing eight, and a shooting attack at a political youth camp, killing 69. He admits to the attacks but rejects criminal guilt. If convicted he would face a maximum sentence of 21 years in prison, though sentences can be extended if a criminal is considered a menace to society. If declared insane by the court, he would be committed to psychiatric care. Both sides can appeal the ruling to a higher court.