Well unless the suspect was flailing around I can't imagine there being "spatter" so much to be analyzed by investigators. Granted a sword would yield a different effect and may cause more "spatter" to look into. LE did say they were looking for 'specific' pieces of evidence, which would likely include the murder weapon they suspect would be used. I think it could have been something either manufactured by the suspect, or a simple bat, club, sword, gun, or something of the like which would ended up causing a "spatter" situation. I just don't think the theory posted about using something like ether to incapacitate the victims before the slaying is a viable scenario given the LE comments provided in the media.