John Barr joins OTL to report that former USA Gymnastics doctor Larry Nassar has been sentenced to 60 years in prison for obtaining and possessing child pornography. (2:40)

GRAND RAPIDS, Mich. -- A federal judge declared former gymnastics doctor Larry Nassar a threat to children Thursday morning and sentenced him to 60 years in prison on child pornography charges -- essentially a life sentence for the 54-year-old former physician.

Nassar is also awaiting sentencing for 10 state counts of first-degree criminal sexual conduct, which he pleaded guilty to in November.

Several of the women who say Nassar abused them filled the federal courtroom with their families in Grand Rapids, Michigan, as Judge Janet T. Neff told Nassar that he had violated the most basic principle of medicine: first do no harm. She said he used his position of authority to sexually assault scores of young women during a decades-long career as a renowned doctor with USA Gymnastics and Michigan State University.

"It's imperative Mr. Nassar be deterred as long as possible," Neff said before delivering the maximum allowable sentence for his three federal crimes. "Mr. Nassar was, is and, in my view, will continue to be a danger to children. He has demonstrated that he should never again have access to children."

Nassar pleaded guilty in July to charges of obtaining and possessing child pornography as well as an additional charge of attempting to destroy evidence. He was first indicted on the child pornography charges last December. Each of the three charges against him come with a maximum penalty of 20 years in prison. Neff ordered him to serve each of those 20-year sentences consecutively, meaning, if he is still alive, Nassar will be 114 years old when the last of them is finished.

FBI agents found more than 37,000 illegal pornographic images on an external hard drive in a curbside trash bin when they searched Nassar's Holt, Michigan, home in the fall of 2016. Some of the "shockingly large collection" of images, U.S. attorney Sean Lewis said, depicted children who were "very young to teens, children being raped, sexually molested, digitally penetrated."

The first-degree criminal sexual assault charges against Nassar stem mostly from incidents in which he sexually assaulted young women who came to him for medical care. Many of the 125 women who filed police reports against him in those cases said he used his hands to penetrate them -- some when they were younger than 13 years old -- and claimed it was part of a medical procedure. He admitted in court last month that what he was doing was not a legitimate medical procedure.

Neff said it was necessary to take those offenses into account when gauging the threat he posed to society.

The FBI also said it found videos that they believe showed Nassar sexually assaulting children in a pool. Special agent Rod Charles testified last December that the garbage pick-up crew was behind schedule on the day of the FBI's search, which gave officers time to check his trash bin.

Neff took into consideration written victim statements, including from U.S. Olympian McKayla Maroney.

"It started when I was 13 years old, at one of my first national team training camps, in Texas, and it didn't end until I left the sport," Maroney wrote in her letter to the court. "Because the national team training camps did not allow parents to be present, my mom and dad were unable to observe what Nassar was doing.

"He abused my trust, abused my body and left scars on my psyche that may never heal," Maroney told the court in her letter. "Larry Nassar deserves to spend the rest of his life in prison."

Among the women to file complaints against Nassar was U.S. Olympic gymnast Aly Raisman. She initially discussed being abused by Nassar on "60 Minutes" last month and wrote about the sentencing in a piece on The Players' Tribune on Thursday.

"Soon after Larry pleaded guilty to federal child pornography charges, I was informed that I could submit a Victim Impact Statement to the court for sentencing consideration. If I wanted, I could also request to read the statement in court on the day of sentencing," Raisman wrote. "Deciding to write the letter was a relatively easy decision. Deciding to read it in court, in front of Larry, was not easy."

Raisman wrote that she decided to read the letter, but Neff ruled last week that victims' statements would not be used in court and instead would be read by the judge privately.

"I was also disappointed that the other survivors wouldn't be given the choice to speak because they may have found it healing in some way," she wrote.

Nassar admitted in July that he also paid to wipe clean the hard drive of a Michigan State University laptop on Sept. 19, 2016. He was fired the following day and was required to return the computer to the school. He said in court that he knew he was under criminal investigation when he had the laptop's memory erased. Neff said that Nassar's attempts to destroy evidence showed that he clearly understood the seriousness of his crimes.

Nassar asked the judge for leniency in court Thursday, saying, "I've been battling with this disease for a considerable period of time." He compared his actions to alcoholism and said as a man of faith, he prayed for forgiveness.

"I really did try to be a good person," he said. "I really tried to help people."

Neff said that Nassar's collection of child pornography satisfied the same sexual gratification that he sought while abusing other victims. She said that despite the fact that Nassar self-reported a good upbringing and was well-educated, he allowed "his dark side" to play out privately for decades. In the process, she said, he destroyed the sense of self-worth for scores of girls and young women.

"You have to wonder whether he felt omnipotent," Neff said. "Whether he felt he was getting away with something so cleverly."

Nassar's attorneys objected to the three sentences being enforced consecutively. Neff said Nassar had two weeks to appeal her decision.

More than 140 women have filed lawsuits against Nassar, USA Gymnastics, Michigan State and high-ranking officials from both institutions.