A gunman who shot and killed six people in a shopping mall before committing suicide should not have been granted a permit for the three weapons he used, police and prosecutors said Monday.
The April 9 shooting shocked this nation where gun ownership is tightly regulated and mass shootings are a rarity, and sparked a review of weapon permit regulations.
Investigations into the shooting spree concluded that the shooter, 24-year-old Tristan van der Vlis, was a gun-obsessed paranoid schizophrenic who believed he heard voices of the dead and wanted to punish God "for all the suffering and evil in the world," said prosecutor Kitty Nooy.
Van der Vlis spent hours trawling the Internet for information about other mass shootings in the United States, Germany and Finland, particularly the 1999 Columbine High School shootings, said police officer Jaco van Hoorn.
Nooy also said that one of Van der Vlis' acquaintances will be prosecuted for allegedly knowing about Van der Vlis' plans to kill himself and others and failing to inform the police. The offense carries a maximum one-year sentence.
Police say Van der Vlis used a semiautomatic rifle, a pistol and a revolver in his three-minute rampage and that he had a permit for all the weapons.
However, Police Corps Chief Jan Stikvoort said the permit should not have been granted in 2008 because Van der Vlis had been involuntarily admitted to a psychiatric hospital. Police were involved in the hospitalization in 2006, but nobody mentioned it when Van der Vlis' gun permit application was being assessed.
"It is terrible that this happened," Stikvoort said. "It is my responsibility to ensure it never happens again."
Van Hoorn said Van der Vlis was wearing a bulletproof vest under a T-shirt during the rampage and that he had fitted a laser sight to his Smith & Wesson semiautomatic rifle.
Van Hoorn said the shooter parked his Mercedes outside the Ridderhof shopping center, grabbed his three guns from the trunk, shot his first victim dead in the parking lot and then walked into the mall shooting a hail of bullets from the semiautomatic rifle.
When he had fired all his rounds from the rifle, he discarded it and began shooting with a Taurus .44 pistol. He then dumped that gun and grabbed his Colt .45 revolver, which he used to shoot himself dead between the cash registers of a supermarket.