A juror who cast one of the unanimous votes to convict a white former Minneapolis police officer of killing George Floyd said deliberations were primarily spent trying to convince one person who was uncertain about part of the jury instructions.

Brandon Mitchell is the first juror that deliberated in Derek Chauvin’s trial to talk publicly about his experience. An alternate juror who was dismissed before deliberations, Lisa Christensen, spoke to reporters last week, saying she would have voted to convict Chauvin.

“I felt like it should have been 20 minutes,” Mr Mitchell, 31, said of the deliberations, which led to Chauvin’s conviction on April 20 on all counts: second-degree murder, third-degree murder and second-degree manslaughter.

Mr Mitchell, who is black, told ABC’s Good Morning America that much of the time in deliberations was spent going over terminology and “making sure we understood what exactly was being asked”.

The identities of jurors and alternates are protected under a judge’s order.

“I think the one juror that was kind of — I wouldn’t say slowing us down — but was being delicate with the process, more so, was just kind of hung up with a few words in the instructions. They wanted to make sure they got it right,” Mr Mitchell said.

Mr Mitchell, who first shared his story with gospel artist Erica Campbell on her podcast, wrote in his jury questionnaire he wanted to serve as a juror “because of all the protests and everything that happened after the event. This is the most historic case of my lifetime, and I would love to be a part of it”.

He speculated that he was picked for the jury because he was mild-mannered. He said the images during the trial trouble him.

“It was just dark. It felt like every day was a funeral and watching someone die every day,” Mr Mitchell told CNN. “It was tense every day. I wasn’t nervous, but it was stressful. It was a lot of pressure.”

Prosecutors said Chauvin pinned Mr Floyd, a black man, to the pavement outside Cup Foods in Minneapolis for nine minutes and 29 seconds on May 25. Mr Floyd had been accused of passing a counterfeit 20 dollar note at the store. Three other officers, since fired, face trial in August.

Prosecutors played a wide range of videos for the jury, including teenager Darnella Frazier’s bystander video that was seen worldwide in the hours after Mr Floyd’s death. That video and the officers’ body camera video captured bystanders shouting at Chauvin and the other officers to get off Mr Floyd, warning that they were cutting off his breathing and asking them to check for a pulse.

Mr Mitchell told Good Morning America that he did not think the jury was affected by tensions in Minneapolis or concerns about what effect their verdicts would have. Mr Floyd’s death triggered worldwide protests, violence at times and a furious re-examination of racism and policing in the US

“We weren’t watching the news, so we don’t know what was going on. We were really just locked in on the case. There was so much stress coming through the case. Those things are so secondary because you’re literally, throughout the trial you’re watching someone die on a daily basis. That stress alone is enough to take your mind away from whatever’s going on outside of the four walls of the courtroom,” he said.

Mr Mitchell also said he thought Chauvin hurt himself by choosing not to testify.

“It probably was to his detriment that he didn’t take the stand because people were curious on what his thoughts were throughout the entire incident,” he said.

In the wake of the attention and weighty deliberations, Mr Mitchell said he has been decompressing.

“I’m starting to feel like the weight is lifted off my shoulders now,” Mr Mitchell said.

Mr Mitchell also said he does not worry about his safety for breaking his silence.

“I’m a person that kind of thrives in the positives. So I’m not too much concerned about that. Nor do I dwell on negativity,” he said.