Colorado authorities have determined that 1,211 prisoners possibly have errors in their sentencing documents that reduced their prison sentences, the Denver Post reports. That is 53 percent of the total reviewed in an audit. The review found that 1,060 cases, or 47 percent, are acceptable, according to the Colorado Department of Corrections and the Colorado Judicial Department. Judges are reviewing case files so they can decide which cases should be amended. In some cases, offenders are being returned from parole or community supervision and some offenders are being notified of longer prison sentences. The review came after it was learned that parolee Evan Ebel, suspected of killing former corrections chief Tom Clements and pizza delivery driver Nathan Leon, was released four years early because of a clerical error.