Dutch police have reportedly discovered a disturbing suicide note from the machine gun-wielding man who killed six people and injured eleven others before fatally shooting himself at a shopping mall outside Amsterdam on Saturday. Tristan van der Vlis, 24, was allegedly a member of a gun club and wrote a suicide message revealing that explosives were hidden at other local shopping malls, which are now being searched. The shooting occurred at the Ridderhof mall in Alphen aan den Rijn. “You hear about this sort of thing happening at American schools and you think that's a long way away," said Rob Kuipers, 50, a project manager. "Now it's happened here in the Netherlands."