I agree with the fact that there were several other suspicious factors in this case above & beyond the missing children - yes, definitely. But, I still stand by my point that there are a plethora of missing persons cases that occur everywhere & only a small fraction get any attention. I.e., this case could easily have fallen through the cracks if the authorities involved hadn't put the pieces together, etc. - as we see in numerous other cases.
In other words, AFAIC it was unusual that the case against these two was pursued as aggressively as it was. As was said, these two perps. almost got away with this. Thankfully, they didn't.