- Police are initially seeking to hold Philip Manshaus in custody for four weeks on suspicion of murder and breach of anti-terrorism law.
Manshaus, who briefly smiled at photographers, does not admit to any crime, his lawyer said earlier.
Eyewitnesses said Manshaus entered the al-Noor Islamic Centre with several guns, but was overpowered by a 65-year-old member of the mosque, who managed to wrestle away his weapons in the fight that followed.
Manshaus did not speak while reporters were present, but smiled several times.
“He is exercising his right not to be interrogated,” his defense attorney, Unni Fries, told Reuters. “He is not admitting any guilt.”
Manshaus, a 21-year-old living near the mosque just outside the Norwegian capital, had expressed far-right, anti-immigrant views before the attack, police said earlier.
Online postings under Manshaus’ name, made shortly before the attack, expressed admiration for the massacre at two New Zealand mosques in March by a suspected right-wing extremist, in which more than 50 people were killed.
Reuters could not independently verify that the postings were made by Philip Manshaus.
A judge is expected to rule later in the day on the police request to formally detain him, the Oslo District Court said.
Police are seeking to hold Manshaus on suspicion of murder, as well as of breaching anti-terrorism law by spreading severe fear among the population.
“The prosecuting authority will request that the person charged be remanded in custody for four weeks, with a ban on visits and communication, without access to the media and in solitary confinement,” the police said in a statement.