Here are the key unanswered questions about James ‘Whitey’ Bulger’s killing

James “Whitey” Bulger (left).US attorney's office via Associated Press/File 1980

In the wake of James “Whitey” Bulger’s killing on Tuesday, came dozens of unknowns. How did it happen? Why was the notorious Boston gangster sent to the Hazelton prison in the first place? At this point, the questions outnumber the answers. Here’s a look at what we know. And what we don’t.

Who killed Whitey?

The first question in any killing — who did it?

In this case, there appear to be at least some answers.

Two inmates were under investigation Tuesday for the killing of James “Whitey” Bulger at a federal prison in West Virginia, including Fotios “Freddy” Geas, 51, a West Springfield Mafia hit man serving a life sentence for the 2003 slaying of the leader of the Genovese crime family in Springfield, according to several people briefed on the attack.

Geas and the other inmate had been placed in lock-down Tuesday, pending the investigation, according to a person familiar with the investigation.

Still, as of Wednesday afternoon, no charges had been announced in the attack.

How did they kill him, and why weren’t guards able to stop it?

Geas and the other inmate under investigation were captured on video surveillance entering Bulger’s cell around 6 a.m., according to one person briefed on the attack. Bulger was found unresponsive about two hours later, at 8:20 a.m., badly beaten with his eyes nearly gouged out, according to people briefed on the attack.

But it remains unclear exactly how other inmates managed to enter his cell, why the attack wasn’t prevented — or stopped sooner by guards — and why it took so long for staff to find Bulger.

Authorities provided few details about the killing.

Why was Bulger even at the West Virginia prison in the first place?

Bulger was killed within hours of arriving at the US Penitentiary Hazelton.

He was sent there after a quick stop at an Oklahoma City transfer site. Before that, he had been incarcerated at a Florida prison for several years until last week, when the transfers began.

It’s unclear why he was moved. One person familiar with the situation said Bulger’s health had declined, prompting speculation that he was going to be moved to a federal medical facility. But another person said he had also had disciplinary problems in Florida.

USP Hazelton is a high-security prison in Bruceton Mills, W.Va. It is not a medical facility.

The relocation has raised eyebrows.

Hazelton has faced serious questions in recent months from federal lawmakers after reports of violence — highlighted by a pair of inmate killings earlier this year — and concerns about understaffing of guards.

There have also been questions in recent years about poor medical care at the prison. An independent review found the 1,300-inmate facility employed just one physician as of August 2014, “which is not adequate to care for the medical needs of all inmates,” and inmates raised concerns about “long response times” for medical care.

Authorities have not said why Bulger was sent to that prison.

To many, the circumstances of his death raised suspicions.

“Obviously it is very strange he got moved from one federal prison to another and ends up dead 24 hours after arriving there,” said Michael Von Zamft, a prosecutor in the Miami-Dade state attorney’s office and part of the team that sent Bulger’s FBI handler to prison for murder.

Why was he allowed to be in the prison’s general population?

Bulger was being held in the prison’s general population housing unit, according to the head of the union who represents workers at the prison.

People with knowledge of the investigation said Bulger had requested to be housed in general population. But some have questioned that decision, including Billy St. Croix, whose sister was killed by Bulger and St. Croix’s father, Stephen Flemmi.

St. Croix said he was surprised that authorities would place Bulger in the general population at a prison where Mafia members and associates were incarcerated.

So far, no further information has emerged to explain the decision.

What, if anything, was done to address past reported problems at the prison?

Bulger’s death was at least the third killing at Hazelton this year.

One inmate was killed in a fight just last month, and another inmate was killed in an altercation the spring. Each incident sparked an outcry from federal lawmakers and union officials about violence and inadequate staffing.

The New York Times reported that a shortage of correctional officers has become chronic under President Trump and that Hazelton has been particularly plagued by violence.

Richard Heldreth, the president of the union that represents workers at the prison, said the facility usually averages one murder a year, but problems have been getting worse because of staffing problems.

He and others have said the prison has been using nonsecurity staff — such as cooks, nurses, secretaries, teachers, counselors, accounting staff, welders, and plumbers — to fill in as guards.

Congresswoman Eleanor Holmes Norton said Bulger’s death “underscores reports of a culture of violence” at the Hazelton facility and reiterated calls for US Department of Justice Inspector General Michael Horowitz to open a formal investigation into problems at the prison.

US Senator Joe Manchin of West Virginia has said he has previously “pressed the Bureau of Prisons and Attorney General Jeff Sessions to follow the law and act on this dangerous situation. They have done nothing.”

The District of Columbia Corrections Information Council, an independent Washington, D.C. agency created to inspect and monitor prisons on behalf of D.C. residents, last week issued a memo to Bureau of Prisons acting director Hugh Hurwitz outlining concerns about the recent violence following a visit and interviews with dozens of inmates at Hazelton.

Michelle Bonner, the information council’s director, said by phone Tuesday that violence at the prison “has gotten worse particularly over the last 12 to 18 months.”

Yet, she said, as far as she knew, prison officials had not announced any reforms. She hoped Bulger’s killing will spur action.

Officials from USP Hazelton and the Department of Justice declined to comment, referring questions to the federal Bureau of Prisons, which has not responded to questions from the Globe about the prison’s history of problems and what has been done to address them.