One of Us: The Story of Anders Breivik and the Massacre in Norway.

Was he mad or was he a political terrorist?
Asne Seierstad, One of Us (Farrar, Straus and Giroux, 2015, translated by Sarah Death).

I read biographies to see how people accomplish so much in spite of their neuroses (or it is because of them?) and there are no simple or easy answers.  Similarly, there are no simple answers as to why some people commit crimes and others, from the same sort of background, do not.  In 2011 Anders Breivik killed eight people with a bomb outside the prime minister's office in Oslo and then proceeded to a youth camp on a nearby island and killed sixty-nine more people, most of them teenage members of the governing Labour Party. Seierstad examines Breivik's life in detail and all the clues missed by Breivik's mother (his father was out of the picture) and the authorities, who acted like the Keystone Cops in their futile attempts to stop the massacre.  Breivik failed at everything he tried to do --from graffiti to selling fake diplomas -- and always blamed others, eventually moving home and devoting himself full-time to computer games, especially World of Warcraft.

Breivik gradually shifted from computer games to anti-Muslim websites, saying to his friends, "The Labour Party has ruined our country.  It's feminized the state  and made it into a matriarchy.  And more than anything, it's made it a place where it's impossible to get rich.  The Labour Party's let the Muslims occupy .." at which point he would start to repeat himself and  his friends would tune him out.  He wrote an unpublished book about the Muslims taking over Norway and rented a farm where he could organize his attacks.

Seierstad does an excellent job of detailing the lives of many of the victims, such as Simon and Bano, who came to Norway to escape the turmoil of the Middle East and became more Norwegian than many of those born in Norway.  It is indeed a question whether anyone could have done anything to prevent the massacre.  Seierstad wisely gives us all the details and lets us draw our own conclusions, including how what happened in Norway relates to the current political situation in America.