Updated

The union representing New York state troopers says it opposes release of sealed documents about the 1971 riot and retaking of Attica state prison in western New York.

The troopers' Police Benevolent Association filed court papers Friday opposing Attorney General Eric Schneiderman's request to open remaining volumes of the 1975 Meyer Commission Report.

In all, 11 prison staff and 32 inmates died -- all but four shot by troopers and guards retaking the prison.

Union President Thomas Mungeer says the union has a duty to protect the rights of troopers forced to testify about their actions during the riot.

Schneiderman says he wants to reveal the fuller history of the nation's bloodiest prison rebellion and answer the questions of families whose loved ones died.