He was once a top political donor. He just died in a prison cell attack.

Mark Grethen was serving 26 years for crimes against kids when another prisoner beat him to death in a Virginia prison.

We trust our justice system to keep people safe behind bars, no matter what crimes they committed. When a prisoner dies in his cell, it shows how easily that safety can break.

WHAT HAPPENED

Mark A. Grethen, 63, died late Tuesday. Police say another prisoner attacked him inside his cell at the Lawrenceville Correctional Center.

Grethen was serving a 26-year term for sex crimes against children. He was once a rich businessman. In 2002, a major political group even named him Republican of the Year. They took the award back when they found out about his crimes.

The man who police say killed him is serving a 22-year term. His past crimes include robbery and hurting a prison worker. Police are treating the death as a homicide.

What the evidence shows

• Grethen was 63 years old when he died inside his cell.
• He was serving a 26-year sentence for six sex crime charges.
• The other prisoner is serving a 22-year sentence.
• The attack took place at a private prison run by The GEO Group.
• Grethen filed dozens of court cases from prison to fight his stay.

THE BIGGER QUESTION

This death raises a deep question about private prisons. Lawrenceville is run for profit by a big company. Do these private setups save money at the cost of basic safety?

When a state locks someone up, it has a duty to keep them alive until their time is served. If the state cannot keep inmates safe from each other, the system is failing.

THE OTHER SIDE

The private firm, The GEO Group, says it works hard to keep inmates safe. State officials say they are doing a full probe into the attack. But critics say private prisons often have fewer guards and more violence than state-run units.

Based on past state reports, private prisons in Virginia have faced many safety complaints.

WHAT HAPPENS NOW

State police will look into how the killer got into Grethen's cell. This event will likely lead to calls for more safety checks at the prison. For regular people, it shows how weak the state's grip on prison safety can be.

WHAT WE STILL DON'T KNOW

1. Why was the other prisoner able to get into Grethen's cell?
2. Where were the guards when the attack took place?
3. Will the state end its contract with the private prison company?