Oslo: Anders Behring Breivik knew it would take practice to be able to slaughter dozens of people before being shot by police.

In a chilling summary, the far-right fanatic claimed on Thursday that he sharpened his aim by playing computer games for more than a year before Norway's worst peacetime massacre.

Breivik told an Oslo court he took steroids to build physical strength and meditated to "de-emotionalize" himself before the bombing and shooting rampage that left 77 people dead.

His lack of remorse and matter-of-fact description of weapons and tactics — he even considered using a flame thrower, was deeply disturbing to families of the victims, most of whom were teenagers.

"They perceive him as evil and dangerous and reopening wounds," said Mette Yvonne Larsen, a lawyer representing the bereaved. Some of them are following the proceedings in court; others are watching it by live video link in more than a dozen courtrooms around Norway.

"It's one thing to read explanations, it's not the same to hear a person present such a message," Larsen said. "I am personally quite shocked."

Norway has been captivated by the trial since it began on Monday. The public TV network NRK is broadcasting live from the court, but isn't allowed to show Breivik's testimony. Pictures of the confessed mass killer, smirking or flashing his clenched-fist salute, clutter newspaper front pages.

For those who have had enough of his antics, newspaper Dagbladet's web site allows users to click a button to read a Breivik-free edition.

But many say finding out what went wrong inside Breivik is crucial for the country to put the July 22 massacre behind it. "We should consider us lucky to have this trial to uncover his thoughts and values," said Oeystein Stoltenberg, 59.