Transcript for Former gymnast who decided to step forward about Nassar: Part 3
I didn't really feel like I could talk to many people for a long time. We're conditioned not to speak up. If something hurts, don't speak up. If someone is screaming at you, don't speak up. He was the olympic doctor, so he must be doing this, you know, to other girls and nobody has said anything, so something must be wrong with me thinking that it was wrong. When I first found out when the article came out, I was honestly in denial. My parents told me he had been arrested. I immediately knew, and my entire world came crashing down. ??? This crew will make a name for themselves tonight. Reporter: It's the summer of 2016, and America is celebrating the success of the "Final five," the gold medal winning usa's women's gymnastics team, which dominated the Rio olympic games. Led by Simone Biles. And veterans gabby Douglas and Aly raisman. That's what a national champion looks like. We are the final five! ??? Reporter: But 5,000 miles away in a dusty newsroom, three reporters for "The Indianapolis star" publish an investigative report on the ugly side of this beautiful sport. Usa gymnastics wasn't always reporting allegations of sexual abuse that it was receiving. From the day after that story was published, Rachael denhollander reached out to us and told us about Dr. Nassar, and that's the first we knew of him. It was just after my 15th birthday. I saw him for approximately a year and he abused me between 10 and 13 times during that timeframe. He penetrated me vaginally and anally. Reporter: That was back in 2000 when Rachael denhollaner was a club-level gymnast. Why did you decide -- did you think maybe now people will believe me? That this door has been cracked open by this fantastic journalism in "The Indianapolis star"? I was very aware of the abuse. I was confident that there were thousands, thousands of victims out there. And I also -- Of Larry? Absolutely. Absolutely. Thousands. Show of hands as you all agree with her that it numbers in the thousands. Absolutely. Astonishing. Reporter: Dr. Nassar is prominent and a revered doctor in gymnastics, so reporter Tim Evans pays him a visit. When I first got there, he was basically pleading that we not write a story, that this was a misunderstanding. He wanted to show me some videos to prove what he was doing or defend what he was doing. In those situations, when he was kind of controlling the narrative, he was much more confident, arrogant. Reporter: Throughout the interview Evans says Larry Nassar maintained his innocence. Denying ever doing anything untoward to any patient. And when "The indy star's" bombshell report comes out detailing the accusations by Rachael and another former gymnast -- The flood Gates opened. Within hours, we had women calling the tip line that was set up by the end of the day we had 12 other survivors who had come forward and it's grown from there. We have over 160 now. My immediate reaction was I can believe that because it happened to me. I called the police department immediately, and I said, I need to file a report. Reporter: As Michigan authorities began to investigate, Michigan state university feels the pressure and fires Larry Nassar. Then two months later. Criminal charges against Dr. Larry Nasser for his predatory, menacing, criminal acts involving a minor. First it started out with three charges of criminal sexual conduct. Then it became around 10. As this investigation kept going month after month, it then became 20. You just saw the number grow and grow and grow. Reporter: Dr. Larry Nassar appearing in court via video conference looking like a shell of his former self. Do you understand the charges are against you, sir? Dr. Nassar's wife supports him 100%. In fact there are hundreds of people who support him 100%. Reporter: Larry Nassar was brought into the Bingham county jail this afternoon. Reporter: Watching on the news, akemi look, learning her former doctor was arrested. My heart dropped into my stomach and my boyfriend was next to me and I just broke. I just completely broke down because I knew that the thing that I never wanted to be true was true. The thing that I pushed away the thing that haunted me every step of my adult life. Tell me about the moment Larry was arrested. How that felt for you knowing especially because that was as a result of the action that you took. I was incredibly grateful when that step was taken. It really wasn't a time I felt like to rejoice yet. Reporter: As the number of accusers begin to mount Larry Nassar's friendly facade, crumbles, when police make a starling discovery in his trash can. Four computer hard drives. On those hard drives are 27,000 videos, pictures of children, girls, engaging in different acts. Some as young as 6 and 7 years old. Reporter: Among the thousands of files on the drives, disturbing home videos of Dr. Nassar. He had a pool party with a couple of young girls, and at that pool party, he was seen digitally penetrating some of these young girls. Reporter: Facing overwhelming evidence, his lawyers strike a deal and Nassar pleeds guilty to possession of child pornography and later to 10 counts of criminal sexual conduct. His medical license revoked as well. But most of America would learn about his despicable behavior with this social media post by Mckayla Maroney. She said she, too, was one of the victims of Dr. Larry Nassar and what made this incredible was so many of us remembered Mckayla Maroney from the olympics, the woman with that classic smirk that even president Obama copied. Reporter: And the woman with that athletic prowess helped vault team usa to gold in 2012. But shockingly behind the scenes. She mentioned that Dr. Larry Nasser abused her during one of these treatments while she was right there at the olympics in London. Reporter: Look at these pictures of Dr. Nassar massaging her leg. Soon, some of her teammates apart of the fierce five said, me too. Gabby Douglas, Aly raisman. I'm so angry that after realizing we were abused, they let him continue to molest other gymnasts. Reporter: Like Simone Biles, the young girl who dazzled the world in Rio tweeted, I too am one of the many girls who were sexually abused by Larry Nassar.
This transcript has been automatically generated and may not be 100% accurate.