The jurors who held the fate of former Minneapolis police officer Derek Chauvin in their hands took their job so seriously that to protect the process they didn't learn one another's names, jobs, family ties or personal interests.

They came from various backgrounds and spanned five decades in age but somehow came to an unspoken understanding early in their three weeks together that they would limit conversation to the weather, a shortage of Cheetos at their snack table and their pizza orders every Wednesday, said Lisa Christensen, who served as an alternate juror in the case.

"We didn't want to do or say anything to jeopardize this process … so we were very careful. We were responsible. We took it seriously," said Christensen. "I felt everybody was coming from a good place, a good heart. I felt everyone was genuine. I don't think there were any ulterior motives at all."

Christensen first recounted her impressions to CBS News and said she is sharing her experience because it's an untold part of the story that adds transparency to the jury process.

Christensen said she was "sad and disappointed" when she was excused Monday afternoon before deliberations began but agreed with the verdicts the jury reached Tuesday after about nine hours and 45 minutes of deliberations — guilty of second-degree murder, third-degree murder and second-degree manslaughter in the May 25 killing of George Floyd.

"I felt [Chauvin] was guilty," she said, adding that a bystander's video of the incident and prosecution witnesses overpowered the defense's inability to deliver on claims that Floyd died of heart issues and a drug overdose.

The 56-year-old Brooklyn Center resident hadn't closely followed news of Floyd's murder last year in south Minneapolis. She had seen short clips of the bystander video a few times on the local news.

She was summoned for jury duty late last year and in December received a thick, 16-page juror questionnaire in the mail. Christensen flipped the first page open and saw the names of the four officers who arrested Floyd and who were charged in his death — Derek Michael Chauvin, Tou Thao, Thomas Kiernan Lane, J. Alexander Kueng.

"You got to be kidding me," she said she thought to herself. "This can't be happening."

She put the packet down on her dresser and walked away. The gravity of the situation was too much. Two weeks passed before she could look at it again. It took another week of fits and starts for her to complete the questionnaire.

By the time jury selection began three months later on March 8, Christensen was confident her number — juror 96 of 326 empaneled for the trial — wouldn't come up. The court needed only 14 jurors, she thought.

But as the second week of jury selection came to a close, Christensen was called to the witness stand and pressed by attorneys for an hour on her thoughts on the case, Black Lives Matter and racial bias in the criminal justice system, among other topics.

"I feel like [Chauvin] took a different role in the situation versus the other officers," she told the court during jury selection. "More like the leader."

Ultimately, a jury of nine women and five men were seated; six were people of color and eight were white.

Christensen said the worldwide attention focused on the case initially made her concerned about her role and possible backlash. But, she added, she didn't believe she or her fellow jurors would have been influenced by such issues in their deliberations.

"I know you can't please everybody," Christensen said. "We just wanted to get it right; that was the priority. That was the focus and that was the agenda."

The jurors' safety was of such concern that per a judge's order, they secretly met with Hennepin County sheriff's deputies at different locations and were driven to the courthouse in downtown Minneapolis, where 10 to 15 armed National Guard members greeted them at a fenced-off entrance to an underground parking garage.

They heard from 44 witnesses over 14 days of testimony that began March 29. Early testimony from several witnesses who saw Floyd die and pleaded with the officers to relent — including a child, three teenage girls and one teenage boy — was especially hard, Christensen said.

Christensen still can't shake the testimony of Darnella Frazier, who was 17 when she recorded the video of Floyd's arrest that became key to the prosecution's case, and Frazier's then 9-year-old cousin, Judeah Reynolds.

"To this day it's still in my mind that [Frazier is] … apologizing to Mr. Floyd at night because she can't go to sleep," Christensen said. "It's pretty heartbreaking. The 9-year-old, I could feel her sadness."

There were several moments during such testimony where jurors retired to a locked room guarded by a deputy and, overcome by emotion, cast their eyes downward to avoid eye contact and waited in complete silence until their return to the courtroom.

"While we were in there it was just us, you know?" Christensen said. "I feel like even though we didn't talk about it, I felt like we were supported by one another, gained strength. … It was a good group."

Frazier's video was integral to the state's case, she said, adding that the testimony of prosecution witness Dr. Martin Tobin was crucial to establishing that Floyd died of asphyxia while Chauvin knelt on Floyd's neck for nine minutes and 29 seconds.

"It never got any easier no matter how many times we saw it," she said of the video. "I still felt the pain I thought Mr. Floyd was going through. I never understood it any better from the first time I saw it to the last time I saw it."

Chauvin's attorney, Eric Nelson, was unable to raise doubts about the state's case or show that Floyd died of a cardiac arrest affected by drug use, or that Chauvin's actions were reasonable, Christensen said.

The trial consumed Christensen's life. After listening to testimony all day and taking notes on a legal pad that remained in the courthouse, she returned home to rewrite notes by hand about each day's witness. Under an entry for 19-year-old Christopher Martin, the Cup Foods cashier who reported Floyd's use of an alleged fake $20 bill that led to the police being called, Christensen, who used to work in retail management, wrote: "I could feel his guilt. … And it's heartbreaking knowing this young kid feels responsible."

A week before she was excused from the trial, a police officer in her city fatally shot 20-year-old Daunte Wright during a traffic stop after firing a gun when she apparently meant to use her Taser. Christensen watched as smoke from police flash-bang grenades rose into the air about a mile from her home. She listened as hundreds of protesters chanted in the distance.

She was running errands Tuesday afternoon when she heard the jury had reached a verdict. She rushed home to watch the announcement on TV.

"I was like, 'Wow, they really found him guilty on all three charges,' " she said. "I was kind of shocked. I trusted them. I know they worked really well together to come to that conclusion. I knew they had what it took to get the job done."

Christensen, who is white, never imagined herself here — thinking more critically about police reform and racial discrimination in the United States. For the first time, she had difficult but revelatory conversations about race with her roommate, a Black man she has known since she was 18.

Sometime in the next few days, she vowed, she will make her way for the first time to 38th Street and Chicago Avenue, where George Floyd begged for his life, and pay her respects. And in her mind she quietly hopes he's proud of the 14 strangers who gathered in a nearly deserted building locked behind concrete barricades and barbed wire to hear his story and reach a historic decision that reverberated around the world.

Staff writer Paul Walsh contributed to this report.