I cannot imagine that "premediated" doesn't mean something CLOSE to what it means here, can you?
Of course, it can mean what it means here, any time......even a minute or a second before. But how can that involve the father?
What on earth could make them charge "premediated murder" without a body OR evidence of a crime, really?
One of my favorites was when they said the body had been found! And that one of them had confessed.