Anders Behring Breivik, the main suspect in the Norwegian bomb attacks and shootings, has been described by police as a Christian fundamentalist with right-wing views.
The blond-haired 32-year-old appears to have set up accounts on the social networking sites Facebook and Twitter just a few days ago.
Although police have not officially named Breivik as the suspect, Norwegian media identified him as the gunman. Police say the suspect is talking to police and was keen to "explain himself".
Eyewitness reports from the island of Utoya, where the shootings took place, have also described a tall, blond haired, blue-eyed Norwegian man dressed as a police officer.
On the Facebook page attributed to him, Mr Breivik describes himself as a Christian and a conservative. It listed his interests as hunting, body building and freemasonry. His profile also listed him as single. The page has since been taken down.
Police chief Svinung Sponheim said that internet posting by Breivik suggested he has "some political traits directed toward the right, and anti-Muslim views".
Police officials have also said that the suspect appeared to have posted on websites with Christian fundamentalist tendencies.
Mr Breivik had served in the Norwegian military doing national service and had no criminal record according to reports.
He is believed to have grown up in Oslo and studied at the Oslo School of Management, which offers degrees and postgraduate courses.
Government business records show him as the sole director of Breivik Geofarm, a company Norwegian media is describing as a farming sole proprietorship.
The company was set up to cultivate vegetables, melons, roots and tubers, Norway's TV2 says, and speculation in local media is rife that through such a link he may have had access to fertiliser, an ingredient used in bomb-making.
The Norwegian newspaper Verdens Gang quoted a friend as saying that the suspect turned to right-wing extremism when in his late 20s. The newspaper also said that he participated in online forums expressing strong nationalistic views.
A Twitter account attributed to the suspect has also emerged but it only has one post, which is a quote from the philosopher John Stuart Mill: "One person with a belief is equal to the force of 100,000 who have only interests."
As with his Facebook page, the tweet was posted on July 17.