The legal investigation into the accident/deaths has drawn its conclusion. The prosecution held a press conference yesterday, announcing that the accident had been caused by icing, which had blocked the "extension of a flap" when the aircraft was on approach, resulting in the aircraft spinning out of control. Prosecution refered to investigation results of the German BFU (aviation accident investigators), excluding a technical defect or disease as a cause:
http://www.schwarzwaelder-bote.de/in...97e282f70.html
The BFU itself has not released its report yet, though. And the reports from the prosecution's press conference are still a bit vague. Most newspaper reports mention a (single) blocked flap. This would indicate asymmetric flap extension. Another newspaper mentions "blocked extension of flaps" (plural) though, which would indicate a slightly different scenario:
https://www.suedkurier.de/region/bod...372474,9638665