Police seized firearms and explosives along with a computer which contained files in which the 16-year-old declared his intention to "kill at least 25 students and teachers - more than in Columbine". He had hidden a loaded stolen hunting rifle, a carbon dioxide-powered rifle and an air pistol under his bed. State prosecutor Anders Peterson said the boys planned the attack for April 20, exactly five years after the attack in Columbine high school, Colorado.
The 17-year-old has admitted the charges and confessed that the two had planned to go into a classroom and begin shooting. A third boy allegedly involved has not been charged as he is a juvenile.
Other than the boys' obsession with Columbine, the motive for the attack seems to be revenge.
Elsewhere, shots were fired last week at the entrance to GrAnby high school in Uppsala, just one month after several classrooms there were set alight.
Public reaction has focused on why youngsters need to express themselves through violence.
In an interview with Svenska Dagbladet, Ann Hellstromer, a social worker and project leader for the Support Centre for Young Victims of Crime, blames greater social and ethnic segregation. "More and more young people are carrying knives and firearms because they're scared, but also because they want to be shown respect," she said.