A teenager who worked at the corner store George Floyd visited the night of his death testified Wednesday that he felt guilty about the events surrounding Floyd’s killing.

Christopher Martin, 19, took the stand on the third day of witness testimony in the high-profile trial of Derek Chauvin, the former Minneapolis police officer charged with murdering Floyd.

Martin had been working at Cup Foods, a convenience store in south Minneapolis, for just one and a half months when Floyd walked into the store with a friend on May 25, 2020.

Floyd was “talkative” and “very friendly” and appeared to be under the influence of drugs, Martin testified. 

The teen said he later sold Floyd a pack of cigarettes and quickly realized that Floyd had used a counterfeit $20 bill. The store management had a policy of deducting money from the pay of any employee who accepted a counterfeit bill from a customer, Martin testified, so he reported the fake bill to his manager.

The manager then instructed Martin to go outside the store, approach Floyd, who was sitting in a parked car across the street, and tell him to come back inside the store, Martin testified.

Martin and another co-worker followed the manager’s instructions and approached Floyd’s car, where they saw Floyd sitting in the driver’s seat, another man sitting in the passenger’s seat and a woman sitting in the backseat, Martin said. Floyd refused to go back inside the store.

Martin said he then returned to the store and offered to have his pay deducted to end the issue. But his manager instructed Martin to go back to Floyd’s car and ask him once again to come inside, Martin testified.

After Floyd refused a second time, Martin’s manager told another store worker to call 911. Minutes later, Martin said, he saw a bunch of people gathering outside, so he went to check it out. He heard people “yelling” and “screaming” and saw Chauvin with his knee on Floyd’s neck, the teen recounted.

Martin said he watched as the scene unfolded, with bystanders demanding that police officers check Floyd’s pulse as he lay motionless on the ground as Chauvin continued to kneel on him.

Security camera video later showed Martin, wearing a gray sweatshirt, khaki-colored pants and a black do-rag, watching as paramedics loaded Floyd into an ambulance. Prosecutor Matthew Frank, Minnesota’s assistant attorney general, asked Martin what was going through his mind at that moment.

“Disbelief and guilt,” Martin said. Asked why he felt guilt, Martin responded: “If I would have just not taken the bill, this could have been avoided.”

During Martin’s testimony, Judge Peter Cahill called for a 20-minute break after a juror stood up and waved her hand, gesturing toward the door, according to a pool reporter.

The juror, a white woman in her 50s who identified herself as a health care nonprofit executive during jury selection, explained after the break that she had suffered what the judge called a “stress-related reaction.”

“I’m shaky, but better,” she told the court, while the rest of jury was out of the room, reported The New York Times. She said she had been having trouble sleeping at night.

Chauvin has been charged with second- and third-degree murder as well as second-degree manslaughter in Floyd’s death. He has pleaded not guilty to all charges.

Bystander video of Floyd’s arrest viewed millions of times across the world showed Chauvin kneeling on Floyd’s neck as he repeatedly stated he couldn’t breathe. Floyd’s death sparked months of protests against police brutality and a worldwide reckoning with racial injustice.

The person who recorded the viral video ― 18-year-old Darnella Frazier ― testified at Chauvin’s trial on Tuesday. Like Martin, Frazier said she has felt guilty over what had happened that night in May 2020.