5 Takeaways From the Second Week of the Derek Chauvin Trial Witnesses addressed two key issues: What caused George Floyd’s death, and whether Mr. Chauvin violated police policies on the use of force. Hennepin County Government Center on Friday.Credit...Joshua Rashaad McFadden for The New York Times April 10, 2021, 9:00 a.m. ET The first week of the Derek Chauvin trial was marked by emotional accounts from bystanders who witnessed the nine and a half minutes that the police pinned George Floyd to the ground. But the second week struck a different chord, highlighting testimony from medical and law enforcement experts that centered on the conduct of Mr. Chauvin and the cause of Mr. Floyd’s death.