Think Dexter and his blood spatter, and you’ll have an idea of ... Step 3: Slowly mix in the cornstarch. You can add a drop of water to the cornstarch first to keep it from clumping.

which he had easy access to as a blood spatter analyst at Miami Metro PD. For every person Dexter killed, he would cut their cheek, take a drop of their blood, place it in a slide, and keep them ...