Derek Chauvin, the former Minneapolis police officer who was convicted of murdering George Floyd during a 2020 arrest, was stabbed at a federal prison in Arizona on Friday, according to two people with knowledge of the situation.

No details were immediately available on his condition, but one of the people with knowledge of the incident said that Mr. Chauvin, 47, survived the attack.

The stabbing was the latest in a series of high-profile security breakdowns in federal prisons, which have struggled for years with safety and staffing issues. Here’s what we know so far about the attack.

Who is Derek Chauvin, and what was his sentence?

Mr. Chauvin has been serving a sentence of just over two decades in federal prison after he was convicted of state murder charges and a federal charge of violating the constitutional rights of Mr. Floyd. He had been an officer with the Minneapolis Police Department for more than 19 years before Mr. Floyd’s death.

In May 2020, Mr. Chauvin, who is white, knelt on Mr. Floyd, who was Black, for nine and a half minutes as Mr. Floyd lay handcuffed, face down, on a South Minneapolis street corner. Mr. Chauvin was arresting Mr. Floyd on suspicion of passing a counterfeit $20 bill at a convenience store. Officials determined that Mr. Floyd’s heart and lungs stopped functioning while officers were restraining him.

The killing of Mr. Floyd, 46, a security guard and former rapper, was captured on video and widely seen. The death set off protests nationwide against police violence and racism. Three other officers who were at the scene where Mr. Floyd was killed were also later convicted of violating Mr. Floyd’s rights.

In a state court in 2021, Mr. Chauvin was convicted of murdering Mr. Floyd and sentenced to 22 and a half years in prison. He was also sentenced to 21 years in federal prison in a separate federal civil rights case in which he pleaded guilty, severely limiting his right to challenge the sentence.

Where was Mr. Chauvin serving his prison sentence in Arizona?

Part of Mr. Chauvin’s plea deal with prosecutors in his federal case was that he would be allowed to serve his sentence in a federal prison, which is generally considered safer than a state prison.

Mr. Chauvin was at a medium-security correctional institution in Tucson that contains nearly 400 inmates. The facility is part of a federal correctional complex that also includes a high-security penitentiary. The complex overall has nearly 1,800 inmates.

While the facility where Mr. Chauvin was stabbed is run by federal officials, state prisons in Arizona have also had problems.

This year, a district judge issued an injunction that required the state’s corrections department to make changes to its staffing and conditions because the medical and mental health care services were not at constitutional standards.

What other recent high-profile cases of violence have occurred in federal prisons?

In recent years, the chronically understaffed Federal Bureau of Prisons has seen a series of suicides and violent attacks involving some of the most notorious inmates in its facilities. That includes the stabbing earlier this year of Lawrence G. Nassar, the doctor convicted of sexually abusing young female gymnasts. Mr. Nassar was stabbed multiple times in the chest, back and neck this summer at a federal prison in Florida where he is serving a 60-year sentence.

Theodore J. Kaczynski, the man known as the Unabomber, who killed three people and injured 23 in a bombing rampage from 1978 to 1995, died by suicide in June at a federal prison medical center in North Carolina.

In 2018, James Bulger, a gangster from Boston known as Whitey, was beaten to death at a West Virginia federal prison after several management failures and breaches of protocol left him unattended and vulnerable to attacks, the Justice Department’s inspector general found.

A similar environment of dysfunction was pervasive at the Manhattan federal prison where the financier Jeffrey Epstein hanged himself in 2019, the inspector general said in a report this summer.

What is behind the staffing shortages at the Bureau of Prisons?

Federal, state and local law enforcement agencies around the country, especially corrections departments, are struggling to hire and retain employees, many of whom have left to take higher-paying, less demanding jobs. That struggle is especially pronounced at the Bureau of Prisons, which houses about 160,000 inmates at 122 prisons and camps, with a work force of about 34,000 people who often earn less than state and county corrections workers.

The Bureau of Prisons has often relied on teachers, case managers, counselors, facilities workers and secretaries to fill shifts.

About 21 percent of the 20,446 federal positions for corrections officers funded by Congress — amounting to 4,293 guards — were unfilled in September 2022, according to a report in March by the Justice Department’s inspector general’s office.

Union officials contend that some recent incidents of inmate-on-inmate violence might have been prevented with greater staffing levels. The depleted work force, they say, has played a role in attacks on staff members, including in 2021, when a guard at a Florida prison responsible for monitoring more than 100 prisoners was assaulted with a metal shank.

The federal prisons bureau has long been plagued by health and safety problems, physical and sexual abuse, corruption and high turnover in the top management ranks.

Colette S. Peters, who took over as the director of the Bureau of Prisons in August 2022, has said that filling those vacancies was the bureau’s top priority. In a hearing of the Senate Judiciary Committee this September, she discussed steps she had taken to start overhauling the system and urged Congress to provide more funding. But Senate lawmakers criticized Ms. Peters for not providing more information on fixing the system’s problems.

Julie Bosman, Katharine Q. Seelye, William K. Rashbaum, Jay Senter, Shaila Dewan and Danielle Ivory contributed reporting.