MINNEAPOLIS (AP) – The emergency room doctor who pronounced George Floyd dead after trying to resuscitate him has testified that he theorized at the time that Floyd’s heart most likely stopped because of insufficient oxygen. Dr. Bradford Langenfeld was a senior resident on duty that night at Hennepin County Medical Center. He said Floyd’s heart had stopped by the time he got to the hospital, and he was not told of any efforts at the scene by bystanders or police to resuscitate Floyd, though paramedics told him they had tried for about 30 minutes. He took the stand at the beginning of Week Two at former Minneapolis Officer Derek Chauvin’s murder trial, as prosecutors seek to establish that it was Chauvin’s knee on the Black man’s neck that killed him last May.