The Cup Foods employee who accepted George Floyd’s alleged counterfeit bill says he’s experienced feelings of “disbelief and guilt” following his horrific death.

On the third day of Derek Chauvin’s murder trial, prosecutor Matthew Frank played never-before-seen footage of Floyd in the Cup Foods store where he bought a pack of cigarettes. The video showed him flipping through a wad of bills. As he walked through the store, he was captured stretching and even dancing at times.

Former Cup Foods cashier Christopher Martin was then called to the stand to discuss his encounter with the late man. During his testimony, he said that he sold Floyd a pack of cigarettes, realizing afterward that the bill given to him had a blue hue, which is commonly found on the $100 bill.

Since employee’s paychecks are docked for the acceptance of counterfeit bills, Martin said that he and a co-worker ran outside of the store in pursuit of Floyd and witnessed the commotion. “I saw people yelling and screaming,” he said. “I saw Derek with his knee on George’s neck on the ground.”

During cross-examination, Martin expressed his belief that Floyd “maybe didn’t know” that he paid for his cigarettes with a fake bill. “He seemed very friendly, approachable, talkative,” he told jurors. ”He seemed to be having an average Memorial Day, just living his life, but he did seem high.”

In the wake of Floyd’s death, the former cashier said that he’s experienced feelings of “disbelief and guilt.” “If I had just not taken the [$20] bill, this could have been avoided,” he said, adding he sometimes stays up late at night, apologizing to the late man for “not saving his life.”

The former cashier also revealed he’s resigned from his job at the Cup Foods convenience store because he no longer felt safe working there.