A former doctor for the US Olympic gymnastics team has pleaded guilty to multiple charges of sexual assault.
Larry Nassar, 54, admitted abusing seven girls, three of whom were under the age of 13, mostly under the guise of treatment.
A prosecutor said 125 women and girls have filed complaints with Michigan State University police.
Nassar, who lost his licence to practice medicine in April, now faces at least 25 years in prison but the sentence could be as high as 40 years.
Olympic gymnasts Aly Raisman, McKayla Maroney and Gabby Douglas are among the women who have publicly said they were among Nassar's victims.
Some of his accusers - many in tears - attended the hearing on Wednesday in a packed Ingham County courtroom in Michigan.
"For all those involved ... I'm so horribly sorry that this was like a match that turned into a forest fire out of control," Nassar said. "I pray the rosary every day for forgiveness. I want them to heal. I want the community to heal."
Nassar admitted sexually abusing the victims and agreed that his conduct had no legitimate medical purpose and that he did not have the girls' consent.
The plea deal in Ingham County calls for a minimum prison sentence of 25 years, but a judge could set the minimum sentence as high as 40 years. In Michigan, inmates are eligible for parole after serving a minimum sentence. Sentencing was set for January 12.
Judge Rosemarie Aquilina told Nassar: "You used your position of trust... in the most vile way to abuse children. ... I agree that now is a time of healing, but it may take them a lifetime of healing while you spend your lifetime behind bars thinking about what you did in taking away their childhood."
She called the accusers "superheroes for all of America, because this is an epidemic".
The girls testified that Nassar molested, sometimes when a parent was present in the room, while they sought help for gymnastics injuries.
Michigan State University said it was "appalled" by the crimes.
USA Gymnastics said it was "very sorry" any athlete was harmed by Nassar.