In new body camera footage shown to jurors on Tuesday in the trial of Derek Chauvin, George Floyd was seen handcuffed and sitting on the street near a Chinese restaurant, giving his name and birth date to one of the first police officers who arrived at Cup Foods after a clerk called to report that Mr. Floyd had used a fake $20 bill to buy cigarettes. The footage was from the body camera of Peter Chang, a Minneapolis Park Police officer who arrived to back up the two rookie officers who first responded to the scene, before Mr. Chauvin and his partner arrived. Officer Chang’s testimony was the first in the trial from an officer who responded to the incident before Mr. Floyd had died.