Also, before getting too carried away with a mention of 'an entry wound' on Sheila's throat, it's worth noting that only a single entry wound is mentioned on each of the other victims, nobody is suggesting the other victims were only shot once when examined by Dr. Craig, are they?

Another of my hazardous guesses, but I suspect that he has simply referred to a single wound which would have been fatal in each case, in order to base his diagnosis of death upon each of the victims.