The inmate who stabbed Larry Nassar did so because the disgraced former gymnastics trainer made lewd comments while watching the Wimbledon Championships, according to The Associated Press.
Nassar reportedly made a comment about "wanting to watch girls" playing in the women's matches, provoking the attack.
Nassar was stabbed twice in the neck, twice in the back and six times in the chest, according to Joe Rojas, a current longtime employee of the United States Penitentiary Coleman, where Nassar is jailed.
The assailant was identified as 49-year-old Shane McMillan, who was previously convicted of assaulting a correctional officer at a federal penitentiary in Louisiana in 2006 and attempting to stab another inmate to death at the federal Supermax prison in Florence, Colorado, in 2011, according to the AP.
Four other inmates reportedly rushed in and pulled McMillan off Nassar.
Federal officials confirmed to Fox News Digital a stabbing occurred at around 2:35 p.m. ET Sunday and that staff members initiated lifesaving measures. An inmate was taken to a hospital for further treatment. Officials didn't identify the victim or the assailant.
Nassar is serving decades in prison for sexually assaulting gymnasts, including Olympic medalists. He admitted sexually assaulting athletes when he worked at Michigan State University and USA Gymnastics. He also pleaded guilty to possessing child pornography.
More than 150 victims spoke or submitted statements during his seven-day hearing, including Simone Biles. The women sought more than $1 billion from the federal government over the FBI’s failure to stop Nassar when agents became aware of the allegations against him in 2015.
Several athletes said they had told trainers, coaches and other adults about Nassar's two-plus decades of sexual abuse, but it went unreported.
Nassar is likely to spend the rest of his life behind bars, while McMillan is scheduled to be released in May 2046.
Fox News' Ryan Gaydos and The Associated Press contributed to this report.