"Analysis of the remains show that the victims could possibly be Serbian, Globus newspaper wrote."
How would anybody know the difference between Croats and Serbs, aside from personal artifacts?
There were probably personal artifacts in the grave..such as rings, necklaces, earings, and so on.
Also, married Western Christians-such as Catholics or Protestants, including Croats-wear their wedding rings on their left hands, whereas Orthodox Christians, like Serbs, wear their bands on their right hands.