The suspect arrested in today's bombing and shooting attacks in Oslo is 32-year-old Anders Behring Breivik, who is believed to have links to right-wing extremist and anti-immigrant (read: anti-Muslim) organizations. (source: Sky News). And now, he has a Wikipedia page. The Daily Mail has photos.
Here's what Norwegian media are reporting as his Facebook page, and Twitter account. Looks like they were both just activated within the past week, which is all very suspicious.
Aftenposten notes that he is said to be a conservative Christian and a Mason, and into hunting and bodybuilding. He owned a farming company that had access to chemicals believed to have been used for bomb-making.
According to comments attributed to him on various Norwegian right-wing/anti-immigrant forums, he was a fan of an array of white supremacist and anti-Muslim pundits—including some from the US. Assuming it's legit, all of this makes early reports that Muslims were responsible for the attacks all the more regrettable.