Swedish police said Sunday they were still struggling to establish the motive of the man behind the Scandinavian country’s worst mass shooting, five days after the tragedy. A gunman killed 10 people on Tuesday after entering the Campus Risbergska,

The king and queen visited the scene of the tragic event that occurred on Tuesday and Swedish flags were flown at half-mast to honor the victims.

Officials in Sweden have vowed to determine why a man killed 10 people, and apparently himself, in an unprecedented attack that's shaken their "society to its core."