OSLO, Norway — The self-described perpetrator of one of the worst modern mass murders in peacetime told Norwegian authorities that he expects to spend the rest of his life in prison but two other cells of his terror network remain free, officials said today.

Anders Behring Breivik has admitted bombing Norway's capital and opening fire on a political youth group retreat, but he entered a plea of not guilty, saying he wanted to save Europe from Muslim immigration.

Prosecutor Christian Hatlo said that Breivik was very calm and “seemed unaffected by what has happened.” He said Breivik told investigators during his interrogation that he never expected to be released.

Police also announced that they had dramatically overcounted the number of people slain in a shooting spree at a political youth group's island retreat and were lowering the confirmed death toll from 86 to 68.

The overall toll in the attack now stands at 76 instead of 93. Police spokesman Oystein Maeland said that higher, erroneous figure emerged as police and rescuers were focusing on helping survivors and securing the area, but he did not immediately explain more about how the overcounting occurred.

Police also raised the toll from a bombing outside the government's headquarters in Oslo before the shooting spree, from seven to eight.