A gunman has killed 10 people at a college in the town of Kauhajoki in Finland before shooting himself and later dying in hospital.
Media reports named the gunman as Matti Juhani Saari, 22, a trainee chef at the vocational college.
The suspect posted a video of himself on the internet last week firing a gun.
As a result of this, police interviewed him on Monday but decided they did not have enough evidence to revoke his license, the interior minister said.
Matti Juhani Saari fires a pistol in a photo posted on his website before the killings
The minister, Anne Holmlund, said an investigation would now try to determine whether mistakes were made.
Prime Minister Matti Vanhanen said this was a “tragic day” for Finland.
The attack echoed a shooting spree at a Finnish school last year which left nine dead, including the gunman, who had also posted an internet v ideo.