the attacker wore a gunshot - proof vest under his clothes and a backpack containing a knife , an axe and a machine pistol . two other knives were finds beside the crime scene . the prosecutor confirmed that the man ' s face was plastered white with burning eyes as he committed the crime , which led international media to make comparisons to the joker , the superhero from the titans novels . " i have a problem , " the killer told the first officer he encountered , after which he soon shot her , and continued his rampage . some female day cared supervisor attempted to disarm the killer while others locked the doors . the killer targeted employees trying to carry weapons to safety .
Joker appears in the Batman series.