Oslo, July 27 The lawyer defending Anders Behring Breivik, who has admitted carrying out the shooting in Norway capital Oslo, said his client was probably "insane".
The bombing in Oslo and the shooting on a nearby island killed 76 people.
Breivik is being charged with terrorism and police are considering charging him with crimes against humanity, which carry a possible 30-year sentence, BBC reported.
Breivik's lawyer Geir Lippestad said: "This whole case indicated that he is insane."
He claims his client believed that he was in a war and that he would be vindicated in 60 years' time.
A medical evaluation would be carried out to establish Breivik's psychiatric condition, Lippestad said.
Breivik also told his lawyer he was part of an anti-Islam network that had two cells in Norway and several more abroad.
Though police have cast doubt on such claims, they were still investigating them.
Lippestad also said his client had used "some kind of drugs" before the crime.