A FEW YEARS AGO, Solicitor Barney Giese had to call in SLED to get Richland County officials to notify police rather than doing their own internal investigations of assaults and other crimes committed at the county jail — some allegedly by jail employees.

The solicitor had to intervene because the county was violating the public trust in a most basic way: You don’t allow someone with a stake in the outcome to determine whether a crime has been committed. People investigating their own organization too often will give their colleagues the benefit of the doubt; at worst, the practice can lead to a cover-up.

But according to a disturbing new report, this principle is routinely ignored with allegations of abuse and neglect in the state system that cares for those who are least able to defend themselves — people with mental retardation, autism and developmental disabilities.

The report, by the government-funded oversight group Protection and Advocacy for People With Disabilities, found “a breakdown in investigating widespread incidents of sexual and physical abuse and neglect among South Carolinians with disabilities under the care of state-funded agencies.”

Troubling cases of abuse and neglect had already come to light at the private Babcock Center and the state-run Midlands Center. But this report, which reviewed a sample of 50 cases over a two-year period, dispelled any notion that those were isolated problems, and underlined the need for reform of the laws and the culture throughout the state’s residential care system.

The Department of Disabilities and Special Needs, which oversees this system, responded by saying it follows the law — a law that allows the agency to decide which allegations are serious enough to be reported to police, and which it will handle internally, if at all.

But even if that is true — and the report says it isn’t — it is no excuse. The law merely allows the agency to investigate some allegations internally; it does not mandate it. Nothing prevents the agency from reporting all allegations to police.

The fact that it chooses not to do this — and that it sees nothing wrong with the way it handles the abuse of those in its care — underlines our concern that there is a serious problem in the culture of the agency. And it suggests new management may be needed.

The agency’s director works at the pleasure of an eight-member board of part-time commissioners — a system Gov. Mark Sanford and some advocates for the disabled correctly contend allows it to get away with providing inadequate protection for those in its care. But while we agree that the department should report directly to the governor, Mr. Sanford already has the tools to force change: State law allows him to replace every member of that governing board with new commissioners dedicated to protecting the disabled rather than protecting the agency and its contractors.

This report suggests that, unless agency officials can make a better case than they have so far, the governor should do just that. And when the Legislature convenes in January, it should make sure that vulnerable adults in state care are protected. That should start with requiring that independent investigators review all allegations of abuse and neglect to determine whether they are serious enough to be reported to police.

One way to judge the values of a society is to look at how it treats its most vulnerable members. In light of this report, our society does not look very good.