Former USA Gymnastics team doctor Larry Nassar sexually assaulted, abused, and traumatized hundreds of young women. Senior FBI officials knew about the abuse and at first, did little to stop it, according to a new Department of Justice report released Wednesday.

The 119-page document comes after an investigation into the FBI’s handling of allegations of sexual abuse against Nassar, who has since been sentenced to at least 300 years in prison for his crimes.

“The DOJ Office of the Inspector General (OIG) found that senior officials in the FBI Indianapolis Field Office failed to respond to allegations of sexual abuse of athletes by former USA Gymnastics physician Lawrence Gerard Nassar with the urgency that the allegations required,” concluded a press release accompanying the report. “We also found that the FBI Indianapolis Field Office made fundamental errors when it did respond to the allegations, failed to notify the appropriate FBI field office (the Lansing Resident Agency) or state or local authorities of the allegations, and failed to take other steps to mitigate the ongoing threat posed by Nassar.”

In July 2015, USA Gymnastics had already conducted an internal investigation into Nassar based on sexual assault allegations from multiple gymnasts. That same month, USA Gymnastics President Stephen Penny, Jr. reported at least three gymnasts’ sexual assault allegations to the FBI’s Indianapolis Field Office.

In a meeting with the FBI, Penny provided the names and contact information of three gymnasts, all minors, who had been sexually assaulted. Penny even “provided the FBI with a thumb drive containing PowerPoint slides and videos that Nassar had provided to USA Gymnastics of Nassar performing his purported medical technique on athletes,” according to the report.

Subsequently, USA Gymnastics advised Nassar not to attend USA Gymnastics events and Nassar retired from his position in September 2015. He kept his positions at MSU, Twistars USA Gymnastics Club, and Holt High School.

For six weeks, the Indianapolis Field Office conducted what the report called “limited” follow-up, reviewing the thumb drive and calling one of the three athletes they knew had been assaulted. The office did not formally document any of its investigation, nor did it conduct further investigation.

Additionally, after concluding they did not have venue to proceed with the case, the Indianapolis Field Office failed to “transfer the matter to the FBI office (the Lansing Resident Agency) where venue existed for the potential federal crimes being considered, even though it … had told USA Gymnastics that the transfer had occurred.”

Eight months after the Indianapolis office failed to act, USA Gymnastics reported the same allegations to the Los Angeles Field Office. Officers in Los Angeles asked the Indianapolis office what formal investigative steps they took to address prior claims, but found no evidence that the Nassar allegations were even filed as a formal complaint. The Los Angeles office launched a full-scale investigation, but “did not take any action to mitigate the risk to gymnasts that Nassar continued to treat.”

In August 2016, a gymnast who accused Nassar of assaulting her when she was 16 notified the Michigan State University Police Department. The Indianapolis Star ran a story on past allegations against Nassar and soon, the MSUPD was flooded with reports of more allegations. In September 2016, the MSUPD finally obtained a search warrant and infamously found Nassar’s child pornography stash at his residence.

Only after that did the FBI’s Lansing Resident Agency open its Nassar investigation in October 2016.  Neither branch in Indianapolis or Los Angeles had alerted the Lansing agency, despite the fact that Nassar worked (and found many of his victims) in Lansing.

In the time it took the FBI to conduct a proper investigation — from July 2015 to September 2016 — Nassar sexually assaulted over 70 young athletes. Three of Nassar’s sexual assault convictions stemmed from abuse that took place at children’s gymnastics club Twistars, over 100 sexual assault allegations came out of Nassar’s time at MSU and at least three students said they were assaulted in the Holt athletic building.