Even prior to Pogba disappointing for United this season I would have been on board with this. Goals = money.
Found evidence at the scene that suggests an islamic terror attack. Said they haven't ruled out it being someone trying to pin it on that either.
http://soccer.nbcsports.com/2017/04/12/islamist-suspect-held-in-dortmund-attack-investigation/ Looks like they were also trying to pin it on left wing extremists too, but that was shot down.