New Documents Confirm Police Abuses in 1971 Attica Prison Riot

It has been more than 40 years since the most deadly prison rebellion the U.S. ever seen, and now new evidence has come to light that injured inmates of Attica in New York were beaten with clubs and had wounds corresponding with torture.

The testimonies, some made public for the first time, come from a doctor and National Guardsmen present at the 1971 riot, which is now being investigated for violent crimes carried out by the state. State Attorney General Eric Schneiderman requested the documents, which were finally released Thursday, two years ago.

RELATED: New Riot Takes Place in Bolivian Prison

They describe brutality committed by prison staff in the catastrophe that saw 29 inmates and 10 hostages shot dead by prison guards and police officers, and 1,300 prisoners surrender after the five-day standoff.

"Today, we are shining a light on one of the darkest chapters of our history," said Marty Mack, executive deputy state attorney general.

The families of victims have long alleged that such offenses took place and the latest reports confirm their fears. Such accusations were brushed aside in the years after the incident.

Judge Bernard Meyer concluding in 1975 that authorities had not intentionally tried to cover their tracks, but that staff had committed serious errors of judgment.

Judge Meyer did find, however, that prosecution in the aftermath was unfairly weighted against prisoners, with at least 60 of them indicted, compared to just one state trooper.

RELATED: Brazil Prison Riot Demanded Better Living Conditions

"A National Guardsman who treated wounded inmates only to have bandages ripped off, saw stretchers deliberately tilted, saw guards beat inmates on medical carts with clubs, saw a prison doctor pull an inmate off a cart and kick him in the stomach, saw inmates beaten while running a gauntlet," Meyer wrote, in the papers released this week.

A further witness saw  "an inmate with large wounds around his rectum which were not from gunshot," which he later learned to have been inflicted by a broken bottle.