Nassar, 53, and his attorneys entered a plea agreement with the court last week. The agreement suggests sentencing guidelines that, if applied by U.S. District Judge Janet Neff, would put Nassar in prison for 22 to 27 years.
Judge Neff is not required to adhere to the sentencing guidelines laid out in the agreement.
In the agreement, Nassar admitted to knowingly downloading images and videos containing child pornography in the fall of 2004. He admitted to possessing thousands of illegal images and videos from 2003 through 2016.
He also admitted that he attempted to conceal or destroy evidence of those images by paying to have his work laptop wiped clean and by throwing hard drives containing pornographic images in the trash in September 2016. He said he was aware that he was under investigation for criminal sexual behavior at that time.
In addition to possessing child pornography, Nassar has been charged with 25 counts of criminal sexual misconduct in state court and has been accused of molesting more than 100 young women while acting in his role as an osteopathic doctor. His plea in federal court represents the first time he has admitted to committing any crimes.
The U.S. prosecutors, in exchange for Nassar's guilty plea, agreed not to pursue charges in two additional incidents of alleged sexual crimes with minors. In one instance, Nassar allegedly attempted to sexually exploit two minors in his swimming pool in 2015. The other involves "interstate/international travel with intent and engaging in illicit sexual conduct," according to the plea agreement.
Nassar's attorneys said he wasn't admitting guilt in those cases, but he understood the judge could consider those claims when determining a sentence for him.
Nassar will also be required to register a sex offender as part of the agreement and pay restitution to victims of his crimes.
Nassar's three crimes are each punishable by up to 20 years in prison, according to federal sentencing guidelines, and can be enforced consecutively to add up to a 60-year sentence. Neff can decide to sentence him to as many years behind bars as she sees fit. The agreement also makes clear that the federal government has not given up the right to prosecute him for crimes that aren't specifically mentioned in the agreement.
Andrew Birge, the acting U.S. attorney for Michigan's Western District, said the agreement gives all of Nassar's victims an opportunity for vindication. Assistant U.S. Attorney Sean Lewis said in court that the four minors affected by incidents that the government agreed not to prosecute knew the terms of the plea deal and were in favor of it.
"Victims and the public can be assured that a day of reckoning is indeed in Dr. Nassar's future," Birge said in a statement Tuesday. "No one, no matter his station in life, is above the law. Those who exploit children will be found out and they will be held accountable."
Several of Nassar's alleged victims were upset by the terms of the plea deal when it was first reported over the weekend. John Manly, an attorney who is part of a group representing more than 90 women in civil suits against Nassar, told ESPN that his clients have been informed that the U.S. attorneys do not plan to prosecute their cases.
"Dr. Nassar molested young women at the Olympics. He molested young women at national competitions. And our country is not going to charge him?" Manly told ESPN's John Barr. "The message that sends these women is: 'You don't matter.'"
On Tuesday, federal prosecutors appeared to change course, saying additional cases of sexual abuse could be pursued in federal court.
"The plea agreement does not preclude the government from pursuing additional charges against Nassar related to his conduct with other individuals," the Justice Department said in a statement.
That's a welcome development for Jeanette Antolin, a national team member from 1995 to 2000, who alleges she was sexually abused by Nassar dozens of times during medical treatments. Antolin told ESPN she met twice in recent days with special agents from the FBI and federal prosecutors, who briefed her on the government's plan to negotiate a plea deal with Nassar.
"They explained it would have been difficult to prove he traveled outside the U.S. with the intent to abuse us. Well, I worked my butt off everyday to represent my country, you work your butt off and do your job to prosecute him. Clearly there were other national team members abused inside and outside of the U.S. who would want to press charges."
The plea deal also does not impact more than a dozen counts of first-degree criminal sexual conduct for which Nassar is scheduled to stand trial in district court. Those crimes, if Nassar is found guilty of them, could each carry up to a life sentence in prison.
Nassar's attorney, Matt Newburg, said Tuesday that admitting guilt to the child pornography charge does not change his client's claims of innocence on the state charges.
"Dr. Nassar's position on the state cases has not changed and we intend to proceed to trial," Newburg said in a statement. "The plea today was negotiated only to resolve federal charges."
The next step for Nassar in his federal case is to be interviewed by a probation officer for an extensive report that will help determine the length of his sentence. The judge who heard Nassar's guilty plea on Tuesday said sentencing will likely occur sometime in November. Nassar will remain in federal custody until then.