> We need to determine what happened based on what we do know. Incorrect. We need to determine what happened based on all the evidence. We can't just make stuf

> We need to determine what happened based on what we do know. Incorrect. We need to determine what happened based on all the evidence. We can't just make stuff up to fill in the blanks. i.e. If what we know doesn't contain facts essential to the determination, we can't just "think about it" harder.