Doing journalism on the ground, finding sources, fact-checking, following up on leads - not reporting on something as major as this and involving this many people, both perpetrators and victims, before five days later. Seems to have taken a lot longer than usual, unless ZDF always operate this incredibly meticulously (their apology seems to suggest otherwise). Smells of bureaucracy and politics to many, especially considering both the police and justice minister's early public comments.
Equally discomforting, is the fact that there's a police chief suspended not only for dereliction of duty as I first thought, but on allegations of a cover-up.