The family of Joel Seidel, a frail, mentally ill man beaten to death in the Camden County jail three years ago, won a $4 million settlement in its lawsuit against the county - an award that lawyers described as one of the largest of its kind in the nation.

Seidel, 65, of Cherry Hill, was beaten to death after he was placed in a cell with Marvin Lister, a violent schizophrenic who has been committed to hospitals for the criminally insane for more than a decade.

Seidel had been arrested and charged with violating a restraining order, while Lister was in the Camden County jail on charges that he assaulted a doctor and raped a patient at the Ancora Psychiatric Hospital. Lister raped and killed Seidel during a 50-minute window when guards failed to check the cells. Guards were supposed to check the cells every 15 minutes.

Seidel's death sparked a raft of changes at the jail, including more supervision of the mental-health wing and measures to ensure that nonviolent offenders such as Seidel don't get housed with maximum-security inmates such as Lister.

Camden County will pay $1 million of the settlement, and the county's insurance company will pick up $2.8 million of the settlement. The rest will be paid by the company contracted to provide mental-health care to the jail inmates, according to the Seidel family's lawyers.

The settlement was finalized this morning.

"They never should have put Joel Seidel in a cell with Marvin Lister," lawyer Tom Kline said. "And when they did, they sent him to slaughter."

Contact staff writer Troy Graham at 856-779-3893 or tgraham@phillynews.com.