A few points:
1) We know that there was no sign of forced entry but do we (sleuthers) know if any means of entry to the house (doors, windows etc) were unlocked other than the front door? I would assume that if any means of entry or exit were used during the "event", no effort would have been made to lock it again. I would think that if the front door was the only means of entry that was unlocked the next day that would have been the only one used. The Case File would certainly have this information.
2) My understanding is that the "globe" was broken but the light bulb was still intact and was "on" the next morning. What we do not know (because the glass had been cleaned up) is whether it had been broken by someone trying to get at the light bulb to turn if off by unscrewing it or if it was broken during a struggle or by someone carrying something out of the house.
3) There have been several references to a bare footprint, believed to be Stacy’s that either was in the living room pointing towards the front door or the porch pointing away from the door. (I believe the former but I may be wrong). Either way, the significance of it was that it seemed to indicate that Stacy left the house through the front door on her own volition while barefoot. I am not aware that there was any evidence that she had cut her foot on glass from the light.
4) I am not aware that any DNA was ever tested. At the time (1992) only bodily fluid type samples would have been used. Apparently there were no suspicious fingerprints but we don’t know what they found. If there were lots of useable prints but none belong to any "unknowns". It would suggest that the perps spent very little time there while evidence of selective "wiping" would tell us something else again. It is possible that so many people in and out during the day hopelessly corrupted the scene.
5) Any serious struggle between three woman and one or more men would leave some sort of evidence. (Whether it was inside the house or outside) The fact that there was no indication of any struggle suggests that the perp(s) was able to establish control very quickly and easily. This would suggest confidence, planning or criminal sophistication and very likely a firearm. (I suppose any "mess" could have been cleaned up, but why?)
If anyone can correct or elaborate on the above, please do. We all need to get our facts straight.
For #3: I think that it has been assumed the footprint was a bloody footprint because the footprint was attributed to Stacy and the only way to verify that it was her footprint would be through DNA. But we still don't know if this is true or not, so I am not sure about any of it. I suppose there could have been a dirty or muddy footprint from someone being in the yard (I am not sure when the last rain event had happened so I don't know if this could even be the case) and there was enough of a print to be able to size the foot (like in the O.J. case). If each of the three women wore a different size shoe, it would be evident whose footprint it was. I'd also like to add that if it was a muddy footprint, then it means that we still don't know if Stacy ever exited the front door where the broken glass was...
These are just my thoughts and opinions and not fact.