During the murder case, the 22-year-old Snorre Ruch was put on trial together with Varg Vikernes and sentenced to 8 years of imprisonment.

The circumstances surrounding the reason for the murder are not entirely clear, but have been mainly attributed to ideological differences and a power struggle between Vikernes and Aarseth. Vikernes claimed that Aarseth had plotted to kill him and that the murder was committed in partial self-defense. Aarseth was found dead outside his apartment in Oslo with an alleged 23 stab wounds — two to the head, five to the neck, and 16 to the back, though Vikernes claims that the majority of these wounds were received when Aarseth fell on pieces of a broken lamp that he knocked over in the struggle. Vikernes also claimed that there was a financial dispute over the profits from Burzum's first two full-length records (Burzum and Det Som Engang Var) as well as the first Burzum EP (Aske) that were released through Aarseth's record label, Deathlike Silence Records, but Vikernes urges that this was never a reason for the murder.

At the time of Aarseth's murder, Vikernes was playing bass guitar for Mayhem. Aarseth's mother reportedly asked Hellhammer (real name Jan Axel Blomberg), Mayhem's then-drummer, to remove the bass tracks that Vikernes had recorded for Mayhem's first full length studio album De Mysteriis Dom Sathanas. Hellhammer has since claimed that he spread the word to anyone he could that he was going to replace the bass tracks, however the tracks were never re-recorded.

At the time of Vikernes' arrest, police found 100 kg of explosives in his home. What he planned to do with the explosives is unknown.

He is presently serving time at Trondheim Fengsel in Norway.