OMAHA — A historical society suing to obtain the identities of 957 people whose bodies were buried in a former psychiatric hospital cemetery says the state is perpetuating a stigma attached to mental illness.

In a brief filed Monday with the Nebraska Court of Appeals — the latest action in the ongoing appeal — the Adams County Historical Society reiterates its position that a lower court was wrong to let the Hastings Regional Center withhold the names. The bodies were buried in unmarked graves in the institution’s cemetery between 1889 and 1957.

The lower court had based its argument on a federal medical privacy law. It argued that releasing the names would reveal that the person was institutionalized for a mental illness or for a condition serious enough to require institutionalization.

But there is no evidence the people — many of whom were committed to the institution without their consent for any number of health conditions or because of poverty — wanted their bodies buried in unmarked graves, the historical society argues.

“That the state chose to bury these individuals in unmarked graves separate from the rest of the population does not mean that society in 2008 should ignore their plight,’’ the historical society argues in court briefs.

San Francisco attorney Thomas Burke, who represents the historical society, said Tuesday that by refusing to release the identities, the state perpetuates a stigma that these individuals have a lesser right to being recognized after they died than others buried elsewhere.

Burke has argued the historical society doesn’t want access to full patient records, only the names and dates of deaths. He also has said the right to privacy dies with the person and that state law allows public access to death records, including burial information.

The society originally sought the names, it says, because, over the years, it got several requests each month from people trying to find information about relatives.

A spokeswoman with the state Department of Health and Human Services — which administers the Hastings facility — declined further comment Tuesday, noting the state had not yet received or reviewed the briefs filed Monday.

Nancy Kinyoun, the hospital’s health information manager who is named in the lawsuit, has said the names are part of the patients’ medical records and thus can’t be released under state statutes protecting patient privacy. The state Attorney General’s Office upheld Kinyoun’s position in a May 2007 opinion.

The state has followed its arguments with a cross appeal. In documents filed last month, the state argues the historical society fails to show it has a clear right to access the identities and that HHS is not obligated to disclose the identities.

It adds that the historical society has misdirected its request and that the identities can be gathered using the department’s vital records division to get death certificates. The state also disputes the historical society’s argument that doing so requires an attorney or court order and is “unduly burdensome or expensive.’’

The state says the fee for a death certificate is $11.

That process, however, could prove a difficult task because there are no names to request a death certificate, leaving a party to submit a blanket request within a wide time frame that could prove costly.

Burke said that if the process were as easy as the state suggests, the historical society would have never filed the lawsuit.

The historical society is “asking this court to carve out a unique judicial exemption that is inconsistent with existing Nebraska law,’’ the state argues.

The state is asking the court to affirm the lower court’s decision and dismiss the case.