WASHINGTON >> A prisoner suspected of stabbing Larry Nassar at a federal penitentiary in Florida said the disgraced former sports doctor provoked the attack by making a lewd comment while they were watching a Wimbledon tennis match on TV, a person familiar with the matter told The Associated Press.

The inmate, identified as Shane McMillan, 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, court records show.

McMillan attacked Nassar in his cell Sunday with a makeshift weapon, stabbing him multiple times in the neck, chest and back before four other inmates rushed in and pulled him off of Nassar, according to the person familiar with the matter.

Correctional officers assigned to the unit at the United States Penitentiary Coleman responded to Nassar’s cell and performed what officials said were life-saving measures. He was taken to a hospital, where he remained in stable condition today with injuries including a collapsed lung.

Cell doors on most federal prison units are typically open during the day, letting prisoners move around freely within the facility. Because Nassar was attacked in his cell, the incident was not captured on surveillance cameras which only point at common areas and corridors.

McMillan, 49, told prison workers that he attacked Nassar after the sexually abusive ex-U.S. gymnastics team doctor made a comment about wanting to see girls playing in the Wimbledon women’s match, the person said.

The person was not authorized to publicly discuss details of the attack or the ongoing investigation and did so on condition anonymity.

Messages seeking comment were left with lawyers who’ve represented McMillan in his past cases.

Sunday’s attack was the second time Nassar has been assaulted in federal custody. He is serving decades in prison for sexually abusing athletes, including college and Olympic gymnastics stars, and possessing explicit images of children.

The attack underscored persistent problems at the federal Bureau of Prisons, including violence, short staffing and an inability to keep even its highest profile prisoners safe.

The Bureau of Prisons insists that there was adequate staffing at the prison where Nassar was stabbed, about 46 miles (74 kilometers) northwest of Orlando, though documents obtained by the AP show one-third of correctional officer positions remain unfilled at the prison.

In a statement today, the agency said it was “imperative that we increase our staffing levels” and said it was recruiting officers and using financial incentives to try to retain workers. Officials said they are also still working to “tackle the problem violence in our facilities” and have enhanced their security procedures, but would not provide details.

“The BOP takes seriously our duty to protect the individuals entrusted in our custody, as well as maintain the safety of correctional staff and the community,” agency spokesperson Scott Taylor said.

“We make every effort to ensure the physical safety of individuals confined to our facilities through a controlled environment that is secure and humane,” Taylor said. “As we continue to pivot out of a years-long pandemic, there are still challenges to confront and opportunities to improve our agency, protect the lives of those who work for us, and ensure the wellbeing of those entrusted to our custody.”

McMillan is scheduled to be released from prison in May 2046, according to a Bureau of Prisons inmate database and court records, though that could change if he is charged and convicted of attacking Nassar.

McMillan was originally sentenced to more than 20 years in federal prison after pleading guilty in Wyoming to conspiracy to distribute methamphetamine in 2002. He had been expected to be released next year before his convictions for the Louisiana and Colorado prison attacks more than doubled his sentence.

In October 2006, McMillan punched a correctional officer who approached him in the recreation yard at the United States Penitentiary in Pollock, Louisiana, while investigating him for a prior inmate assault, according to court records. The blow knocked the officer to the ground and caused cuts and bruising to his face and nose. McMillan was sentenced to an additional five years.

In November 2011, McMillan and another inmate attempted to kill a prisoner at the federal Bureau of Prisons’ Administrative Maximum Facility in Florence, Colorado, according to court records. McMillan and the other inmate stabbed the prisoner 66 times in a recreation area of the prison, known as the “Alcatraz of the Rockies.” They were each sentenced to an additional 20 years for the attack.

McMillan arrived at the Coleman, Florida, penitentiary last December, according to records obtained by the AP. He’d spent the previous four years at a federal penitentiary in Tucson, Arizona, following stints at federal prisons in Allenwood, Pennsylvania, and adjacent to the Supermax lockup in Colorado, the records show.

Nassar was transferred to Coleman from the Tucson penitentiary in August 2018. His lawyers said he’d been assaulted within hours of being placed in general population at the Arizona prison.