The commanding officer, Niklas Hallgren, tells Swedish Radio that they have reached the conclusion by looking at how the man was dressed, how he chose his victims and from what they have gathered by searching his home.
"We can confirm that this was a racially motivated hate crime partially because the man chose his victims based on the colour of their skin," Hallgren says.
The man has previously shown interest in far-right extremism and Nazism and the helmet he was wearing during the attack resembles the helmets that German soldiers wore during World War II, according to Swedish Television. Police, however, claim that he did not have any ties to any extremist groups.
The school remains closed today while police continue their investigation and there will be psychologists outside the school to give support to those who need it, according to Paul Åkerlund, who is the chairman of the municipal board.
"We will make sure that there are people you can turn to if you need help and that there are places for people to gather to talk about what happened for a long time," Åkerlund tells Swedish Radio News.
Three people died in the attack: one teacher, one pupil and the attacker. Two men are still being treated for their injuries, one of them in critical condition according to police.