Apparently a man from Amsterdam is responsible for murder , Jos Leijdekkers who is very close to Kavacki clan organized the killing. Leader of Kavacki clan was hiding in Amsterdam for some time with help of Jos Leijdekkers also known as El Presidente.
Interesting Jos L. was already the most wanted fugitive in Holland. Jos grew up in Breda, but is currently seen by the police and the judiciary as the 'new number 1' of the dutch underworld. He is still pretty young 30 I think. The police and the Public Prosecution Service released new images of him earlier this month.