On Tuesday, French authorities announced that they had arrested Norwegian black metal musician Kristian “Varg” Vikernes on suspicion of plotting a terrorist massacre. According to Euronews, Vikernes was arrested after his wife purchased four rifles, which police believe he may have planned to use in an attack. But who is Vikernes, and why is the simple possession of rifles enough to make him a terrorism suspect?

Vikernes first emerged on the public scene as a musician, not a criminal. He played bass for the extreme Norwegian black metal band Mayhem and helmed the one-man project Burzum on the side. Norwegian black metal at the time was based heavily on dark, violent and Satanic imagery. An avowed pagan, Vikernes fit right into the scene and embarked on a series of church arsons that destroyed historic wood stave churches across the country.

In 1993, Vikernes stabbed Mayhem bandmate Øystein “Euronymous” Aarseth to death in a fight. The next year, he was convicted of Euronymous’s murder as well as the arson of three Norwegian churches. Vikernes served 15 years of a 21-year prison sentence for the murder and arsons. When Vikernes was arrested, Norwegian authorities found hundreds of pounds of explosives and more than 3,000 rounds of ammunition in his house, possibly to be used in an attack on an anti-fascist Olso punk group. Vikernes was eventually released from prison in 2009, and has continued to make music as Burzum.

Vikernes is an especially violent man, driven by a deeply nationalistic worldview. In the past, Vikernes has identified himself as a neo-Nazi, and while he no longer uses the term to describe himself, it’s clear that he holds sympathetic views towards many neo-Nazi groups. His primary objection to the use of the term “Nazi” to describe his views comes more from a desire not to offend Slavs (though not Jews), among other reasons.

“Naturally I never had the intention to offend or alienate Slavs. … What makes me different from the ‘nazis’ are basically three things; unlike them I am not socialistic (not even on a national level), I am not materialistic and I believe in (the ancient Scandinavian!) democracy,” Vikernes wrote on his website in 2005.

Since the late ‘90s, however, Vikernes has dubbed his extreme right-wing views “odalism,” which he describes as fiercely anti-modern, heavily based on pre-Christian pagan values, and openly racist. Vikernes’ ideology is largely based on pre-Christian Nordic and Germanic beliefs of honor and the fatherland, and he sees himself as constantly on the offensive against any beliefs deemed a threat to a pre-industrial European pagan society, including but not limited to Christianity, Islam, Judaism, capitalism and materialism. Several of Vikernes’ writings hint at the possibility of violent conflict with these forces, leading to his terrorism arrest.

French authorities pointed to an open letter Vikernes wrote to Norwegian mass murderer Anders Breivik as proof of a possible planned massacre. In the letter, Vikernes has condemns Breivik for murdering ethnic Norwegians, but he also rallies against a perceived international Jewish conspiracy to destroy the traditional European identity. Vikernes may insist that he isn’t technically a Nazi, but his letter shows a disturbing, deep-seated hatred of Jews that may hint at the possibility of violence. Additionally, Vikernes was one of some 500 or so people who received Breivik's manifesto before he embarked on his 2011 killing spree.

He wrote: "To Breivik I can only say I hope you do kill yourself. You have killed more Norwegians than the entire Muslim population in Norway has done the last 40 years, and you claim to be a Norwegian nationalist and patriot fighting (alongside your Jewish masters) against Islam, to protect us against their crimes!? I am sorry to say so, but you have made a big mistake. Islam has been imported to Europe by Jews, so that guys like you would run to the Jews and fight for them like you did when you murdered future mothers of Norwegian children. Death to you and to all other 'European' Zionists out there as well! You are the main problem for Europe, because guys like you allow the Jews to run Europe into the ditch."

Later in the essay, Vikernes goes on to describe the necessity of a "final solution" against Jewish forces that he sees as enslaving the European consciousness.

"Today we are on the offensive. For the first time in many decades. The Jews are unveiled as weak and powerless, and they lose more and more of their support in Europe. Every day thousands of Europeans wake up and see the true white light, and they see the true face of the backstabbing, treacherous, money-lending, murderous, coward, pedophile slaver-Jew. The tide has turned, and yet again Europe is about to rid itself of the eternal Jew and his destructive influence, like we have done so many times before as well."

In an interview with Radio Metal, Vikernes discussed the possibility of a violent slaughter against supposedly "invading" forces in Europe.

"When your life is threatened or when the survival of your nation is threatened, you have the right to defend yourself, and violently if necessary. (...) We will eventually revolt when we no longer have the choice and then we will see a massive slaughter in Europe," he told Radio Metal interviewers in 2012.

It's clear that Vikernes subscribes to an especially radical, possibly violent worldview, but does that make him a terrorist? At the moment, that's what French officials are attempting to figure out. Vikernes' French wife Marie Chachet is a member of a shooting club and reportedly purchased the four riles legally using her shooting permit. Given his radical associations and habits of stockpiling weapons in the past, however, French officials are unsure that his wife was simply buying firearms for sport.

“Having received the manifesto before (Breivik) committed his crimes and having been sentenced in Norway in the past for murder, this individual, who was close to a neo-Nazi movement, was likely to prepare a large terrorist act,” French Interior Minister Manuel Valls told Euronews. “The investigation will notably establish the conditions in which these (rifles) were acquired and their real objective."