So, Battler, here's a mystery that you can't solve.
Their father lies dead on the floor with a knife wound through his chin into his brain, avoiding scratching any of his bones. The pool of blood around him only has shoeprints of theirs leading into the kitchen, which leads to my bed where my phone is, but their mom is on the bed with her throat slit and their grandma is on the back porch with a similar wound to their dad. Of course, their prints are on everything because they lived there and do the dishes. But there are no knives out of place or bloody, or even have a small hint of blood on them and their clothes are entirely clean except for the soles of their shoes covered in their dad's blood. The animals are all fed, as they said they was out doing when it happened and they walked in through their dad's blood to get their phone. They called in the murder.
Prove they did it using only what would be viable in a court of law.