The latest report - if it is true - of them being 4 in the car going out, but only 3 coming back is really disturbing. It raises the probability of AH being the murderer by a lot, and even if it's one of the other two, he has been obstructing justice by dumping the body and by not reporting the killing. Looks like either an accident playing with guns or a fight that got out of hand.
Lacking any physical evidence connecting either of the three directly to the murder, as in powder residue or something like that (CSI-guys please step in), it will be down to who turns on the others the fastest.
I'm not a lawyer, but if neither of them spill the beans on the others, lacking any physical evidence, do they just walk free? Or would there be some sort of collective punishment as we know one of them did it? Neither possibility seems reasonable.
I remember a bank robbery in Denmark maybe 20-25 years ago where a cop was shot and killed by the robbers as they escaped. They were later caught but could only be convicted for the robbery, as it was impossible to determine who shot the cop. Would it be the same in this case?