maybe because they are babies and it violates the 4 inch rule....where it's illegal to sell turtles under 4 inches big. Though if you see online most places get around that rule by setting an 'adoption fee' and the turtles are supposed to be for educational purposes only.

i am not entirely sure if in Indiana alligator snappers are a native species, I am not sure where alligator snappers are native, that too could be a reason why it's illegal, they maybe native.

did you find the hatchlings in the wild? if so it's probably best to release them or find a rescue to take them. They get big and angry... def. not a beginner turtle (if there is such a thing...)