GRAND RAPIDS, Mich. Larry Nassar, the USA gymnastics doctor who has sexually assaulted female gymnasts, was sentenced to 60 years in prison on Thursday in his child pornography case.

It is the first of three prison sentences that will likely keep him locked up for decades. Nassar had more than 37,000 images of child porn on electronic devices. Separately, hell be sentenced in state court in January for molesting gymnasts with his hands.

Nassar, 54, worked at Michigan State University and at USA Gymnastics, the Indianapolis-based group that trains Olympians.

Underneath this veneer lurked a predator, Assistant U.S. Attorney Sean Lewis said.

Olympians Aly Raisman, McKayla Maroney and Gabby Douglas say they were victims when Nassar worked for USA Gymnastics and accompanied them at workouts or international events.

Nassar is a monster who left scars on my psyche that may never go away, Maroney said in a letter to U.S. District Judge Janet Neff.

In a court filing, defense lawyers said Nassar deeply regrets the pain that he has caused the community.

The child pornography was discovered last year when Nassar was being investigated for assault.

Aside from the criminal cases, more than 100 women and girls are suing Nassar. Michigan State and USA Gymnastics are defendants in many of the lawsuits.