Wounds may exhibit swelling and abrasions as well as different levels of skin stretch.
The size of the entrance wound is controlled as much by angle of impact as the size of the projectile. Exit wounds, should they exist, are poor determinants because of bullet fragmentation, expansion, instability (tumbling and deflection), and are commonly larger than the projectile's original diameter.
Wound size alone is not a solid determinant, although it can be supportive data.
A far more definitive assessment can be made with ballistics data from the recovered projectiles and fragments from the deceased, wounded, and from the surroundings in the instance of through and through wounds.
Bullet type, weight, composition, diameter (caliber) can all be determinants as to the caliber of firearm, and ballistics markings may identify the firearm by type or even the individual firearm of origin if that has been tested for comparison.
Unfortunately, this ballistics data has not been released, even though there has been considerable time to analyze the physical evidence.
Without that data, it is difficult to definitively state who was shot by whom.
The agencies involved are aware of this.
They are complicit
Did I say size of the hole? The injury caused by above the speed of sound projectiles is easily distinguished from subsonic. All but one GSW among the nine dead were NOT handgun wounds.