Merhaba!
Could you take a look at my translation attempt of this paragraph from press?

Kültür- Sanat kulislerini hareketlendiren İncil´in Jandarma İstihbarat ekipleri tarafından kimlikleri belirlenemeyen "Yavuz" ve "Hacı" takma adlı şahıslardan yakalandığı, 2000 yılında yakalandığı belirlendi. Buna göre Jandarma İstihbarat elemanları "Zafer" ve "Fatih" kod adlı kişilerle irtibata geçerek önce İncil´in CD´sini istedikleri öğrenildi. Ekipler daha sonra alıcı gibi davranıp, operasyon gereği İncil´in fiyatında anlaşmışlar. Ardından Zafer ve Fatih kod adlı şahıslarla Maltepe´de buluşan Jandarma istihbarat ekipleri İncil´i alır almaz gerçek kimliklerini gösterip operasyonu tamamlamışlar. Ancak İncil´in gerçek sahibi olan Yavuz ve Hacı kod adlı kaçakçılar durumun farkına vararak kaçmışlar.

And my translation:

It was stated that the Gospel, which heats the backstage of Culture and Art, has been captured in 2000 by a team of Gendarmerie Intelligence, from persons nicknamed "Yavuz" and "Hacı", whose identity could not be determined. It was learned that accordingly, members of Gendarmerie Intelligence, when contacting persons nicknamed "Zafer" and "Fatih", firstly wanted the CD of the Gospel. Afterwards, the teams behaved like purchaser and, due to (the conditions of) the operation, agreed on the Gospel’s price. Later, the Gendarmerie Intelligence’s teams, which met in Maltepe with persons nicknamed “Zafer” and “Fatih”, after receiving the Gospel and showing their real identity, completed the operation. However, the smugglers nicknamed “Yavuz” and “Hacı”, who were the real owners of the Gospel, ran away when they realized the situation.

I´d like you to tell me if I have made any serious mistakes there
Moreover I would like to particularly discuss the words/phrases which I marked in red, because I am not sure about them...
1.) önce, I´m not sure which part it relates to ...firstly contacting persons, wanted... or ...contacting persons, firstly wanted...
2.) alıcı gibi davranıp, I translated it literally, but I suppose there´s a hidden idiomatic meaning. Unfortunately, no dictionary mentions it.
3.) operasyon gereği, after analyzing more examples with "gereği", I figured out it must be something like according to/due to the conditions of..., but this phrase can´t be found in any dictionary either.
4.) alır almaz, "after receiving" is my guess, but I´m not familiar with such a construction.

Frankly, although my translation makes a sense, I don´t understand the story they are telling there

4. alır almaz ´upon receiving´

It´s a funny expression, where the meaning of the whole is the sum of the constituents: being on the borderline of receiving and not receiving.

alır almaz= as soon as receiving

my try