evidence: On the second day of Derek Chauvin’s trial for the murder of George Floyd, the most powerful testimony came from children. Three high school juniors and a second grader, trying to purchase snacks and a cord to play music in the car, witnessed Chauvin, then a Minneapolis police officer, using his knee to pin Floyd’s neck to the ground outside of Cup Foods. The teenagers recorded the incident on their phones. They heard Floyd call out for help. They saw a firefighter arriving on the scene and demanding a pulse check. And they heard when Floyd stopped speaking and appeared to lose consciousness. [...] [Chauvin] was digging his knee into George Floyd’s neck. He did grab his mace and started shaking it at us.