"I think the first thing is shock, to be honest. I think you can't react the other way. I think everyone in the school is in complete shock," said 24-year-old student Helene Parr, who knows people at the BORG Dreierschützengasse school, where the mass shooting took place.

A 21-year-old man, Arthur A., committed Austria's deadliest school shooting in Graz, killing 10 before turning the gun on himself. Investigations reveal his introverted nature and obsession with online shooting games.

A brutal act of mass violence in Austria has left the nation reeling. On June 9, in the city of Graz, 21-year-old Arthur A. shot and killed 10 people — including eight children — before turning the weapon on himself.

King Charles and Queen Camilla have sent an emotional message to Austria following the shooting rampage in Graz.