I don't know if a stun gun was used during the murder of JonBenet, but it certainly seems possible, if not probable, at this point. There hasn't been any other reasonable explanation for the source of the two sets of marks on JBR's body, at least any explanation of which I'm aware.
Dr. Spitz pointed out the difference between the appearance of stun gun marks found on a dead JBR and those inflicted on a live pig as part of a test. Fair enough. They do look different in color and size. However, different people have entirely different reactions to skin lesions, and maybe pigs do, too. (I don't have a clue about pigs.) Dr. Spitz, being a doctor, should know that, too. Yet, the only comment he made to support his argument that the lesions on JBR were not made by a stun gun was something like, "Just look at the difference". His counter-argument, that the lesions were caused by "snaps", was completely unsupported.
When the stun gun discussion first came into being years ago, the most common argument against a stun gun being used during the murder was that stun guns didn't leave marks. Now, the argument is that they do leave marks, but not the kind found on JonBenet. What about stun gun marks found on another human being? Why did Dr. Spitz not put this to rest by showing the difference between the marks on JBR and those of an actual stun gun victim, hopefully one of approximitely the same age?
Lou Smit, an ex-detective with impeccable credentials, thinks a stun gun was used on JonBenet. He actually solved a murder years ago in which a stun gun was used, so he has experience in the area. Until Dr. Spitz or someone else comes up with some evidence to support the BPD argument that THERE WAS NO STUNGUN, I'll continue to lean off the fence in the direction of the experienced detective who has at least shown us that that stun guns do leave marks, and the spacing of JBR's wounds could easily have been caused by a stun gun.