Espen Andersen Bråthen, a 37-year-old Danish citizen, was arrested Wednesday over the attack, which took place in the Norwegian town of Kongsberg that day.
Police have interviewed more than 50 witnesses, Assistant Chief of Police Per Thomas Omholt told a press conference in Kongsberg earlier Friday, and are checking the suspect’s digital media.
“This is a very serious case for [the] local community and the country. We will find out what has happened,” he said.
“We are working with many hypotheses [regarding the motive], but the main one at the moment is health related,” he added. “The hypothesis around jihad has not been strengthened in the same way as the health hypothesis.”
Police revealed Thursday that Bråthen had converted to Islam and that officers had previously been in contact with him, including over concerns related to radicalization.
Three weapons, including the bow and arrow, have been taken from the suspect, Omholt said. Police declined to share details of the others while they investigate.
The identities of the five people killed have not yet been made public, Omholt added. Police are continuing to work to identify and notify next of kin.
A police statement released Friday afternoon said that further charges could still be brought, since the suspect had also inflicted injuries on three people and had fired arrows at others.
“The homicides were committed both indoors and outdoors, and the perpetrator also made his way into private homes. In addition, he fired arrows at people in public,” the statement said.
“Details about the murder weapons and how the victims were killed will not be released yet. The police are still interviewing witnesses, and we do not want to influence their statements,” Omholt is quoted as saying in the statement. Several victims have also been interviewed, the statement said.
Bråthen has been remanded in custody for four weeks, with the first two in isolation and the remainder subject to a ban on visits, letters and media.
“The person charged has acknowledged the facts of the case, but has not made any statement with respect to criminal liability,” the statement said.
“Due to the health condition of the person charged, he has been committed to a high-security psychiatric ward during his remand period. He will also undergo a full forensic psychiatric examination to determine whether or not he was accountable for his actions.”
A regional police spokesperson told CNN earlier Friday that Bråthen had been handed over to health services and would not appear in court that day.
Bråthen “is not disputing what happened,” the police spokesperson told CNN.
Norwegian Police Security Service (PST) chief Hans Sverre Sjøvold told reporters on Thursday that the attack “appears as if it may be an act of terrorism” but noted that it is important the investigation goes ahead and “we get to clarify what the motives of the accused are.”
Police chief Ole Bredrup Sæverud said Thursday that the police had “received no reports in 2021 regarding radicalization” in relation to the suspect, but that concerns had been raised previously.
Four women and one man were killed in the attack. They were all aged 50 to 70 years, Sæverud said.
People laid flowers and lit candles at a vigil for the victims in Kongsberg on Thursday evening, with more stopping by to pay their respects at the makeshift memorial on Friday.
Newly inaugurated Norwegian Prime Minister Jonas Gahr Støre was expected to travel to the town later Friday.
The tragedy coincided with Gahr Støre’s announcement of the new Norwegian government Thursday. Acknowledging this during a press conference in the capital, Oslo, he called it “a very special day to present a new government” in light of the country experiencing a “horribly cruel attack on innocent people last night.”
He expressed his relief that Norwegian police had arrested the suspect, while emphasizing that the outcome was still “deeply tragic.”
The Prime Minister drew a parallel between Wednesday’s attack and the gun and bomb attacks carried out in Norway in 2011 by far-right extremist Anders Behring Breivik, adding that two ministers in his new government were survivors of those attacks.
“It was an act of terrorism, and this act that happened yesterday naturally reminds us of those who have experienced such terrible things and we will stand by them,” he said.
The Kongsberg attack “shows that our society is vulnerable,” Gahr Støre said, as he stressed that it is “not good for us to conclude what is the motive, what is behind this action.” He said the Norwegian police “must be allowed to finish their work and clarify” such matters but that the attack “emphasizes again that preparedness is a complex task for a society.”
A timeline of the events Wednesday revealed that only 35 minutes elapsed between the first reports to police of a man shooting with a bow and arrow, at 6:12 p.m. and the arrest of the suspect at 6:47 p.m.
The perpetrator was believed to have acted alone, police said.