That's a tough question. I suppose it could be a combination of both Bosnian Serbs and Bosnian Muslims that shot up the warehouse, or it could be one side or the other. It could also be a lunatic from either faction that was loaded up with too much plumb brandy and had too much extra amunition, or it could be the location of a very nasty slaughter. It all depends on who held the area and when and for how long.
I was in Vukovar in 1995 and that warehouse looks like every single building in Vukovar regardless of it was a Croat house, Catholic church, Serb house or Orthodox church.
A building riddled with bullet holes in the former Yugoslavia tells me nothing.
If it was a slaughter and the time was taken to remove the bodies, why not burn down the warehouse? Haven't any of those people seen "Pretty Village Pretty Flame"?
I guess it's the garage area where allegedly 1,000 Muslims were crammed before they were shot, so the story goes. But could 1,000 men fit? Why would the gunfire be concentrated around the doorway off to the side of this, and become much, much more dilute around the garage area if that's where the target was?