(CNN) An alternate juror in Derek Chauvin's trial told reporters Thursday that Dr. Martin Tobin, the soft-spoken doctor who explained how George Floyd died, convinced her of the former police officer's guilt.
"Dr. Tobin was like the turning point for me," said Lisa Christensen. "I appreciate him explaining it in the way that all of us could understand it. I understood what he was saying. I thought it was very powerful -- probably the most important witness they had."
Tobin, a pulmonologist who studies the physiology of breathing, testified that Floyd died of low oxygen due to Chauvin's restraint. Christensen praised the way he narrated key, specific moments in the video that might have otherwise been missed.
"I feel like he could actually point out, going through the video, saying, 'Hey at this instance right here is where Mr. Floyd lost his life,' " she said.
As an alternate juror, Christensen sat through the entire trial but was dismissed prior to deliberations, so she was not one of the 12 jurors who voted to convict Chauvin on two counts of murder and one count of manslaughter.
Still, her comments are the first public indication of what jurors in court every day felt and thought of the case against the former Minneapolis Police officer. Her analysis also fits neatly with what court viewers and legal analysts said of the most powerful witnesses.
In a press conference with the media as well as in an interview on "CBS This Morning," she said she believed Chauvin was guilty.
"I didn't know if he was going to be guilty on all counts, but I would have said guilty," she told CBS.
Christensen spoke to the media Thursday from her home in Brooklyn Center, where during the trial a police officer shot and killed 20-year-old Daunte Wright, sparking protests. She said there were some nights coming home from court that she was racing to beat the curfew put in place after Wright was killed.
"Obviously, living six blocks away, when I stepped out on my deck over here I could see the smoke actually from the smoke grenades. I could hear the helicopters, til about one in the morning, flying over my house. I could actually hear the... flashbangs, and I could hear the chatter of the people and people trying to park all over the place here," she said.
Though she didn't ultimately deliberate, she told CNN that the trial was draining.
"I didn't think it would affect me as much as it has. It was emotional. It was draining. There was lots of nights where I just came home from the trial, and I just went right to sleep, right to bed," she said. "It was an experience, I mean it affected me, you know, more than I thought it would. So yeah, it'll be with me for a while. I hope we did it right and we got it right. We really tried to put all of our effort into it, make the right decisions."
In the CBS interview, she also praised Darnella Frazier, the teenage bystander who took clear and intimate video of Floyd's final moments. At the trial, Frazier testified she lost sleep at night apologizing to Floyd for not doing more to save him.
"She feels responsible in a way, and I feel really bad for her, but I commend her for taking the video because without her I don't think this would have been possible," Christensen said.
By contrast, she didn't think the defense witnesses had a good impact and she had negative views of defense attorney Eric Nelson.
"I think he over-promised in the beginning and didn't live up to what he said he was going to do," she said.
Nelson has not commented to CNN since the verdict.
Christenson expressed discomfort with Chauvin himself, who appeared in court every day but did not testify.
"We locked eyes quite a few times and I was pretty uncomfortable," she told CBS.
Yet she also expressed some empathy for him in her conversation with the media. "I do feel bad for him. Whether, you know, he made a huge mistake and it cost somebody their life... nobody is a winner out of this whole situation. I feel bad," she said.
Christensen said watching the video of Floyd's death, which she hadn't seen in full before, left her in tears a couple times. And she expressed her continued confusion about how a suspected fake $20 bill got so out of hand.
"I just don't understand how it got from a counterfeit $20 bill to a death," she said. "It kind of shocks me."
The jurors in the high-profile case were unnamed and unseen on camera to protect their identity.
In jury selection, Christensen, a White woman in her 50s, said she worked until recently in customer service in a suburban business that was damaged in the civil unrest after Floyd's death. She said she had a "somewhat negative" view of Chauvin, but generally trusts police and believes people who follow their instructions have nothing to fear.