ALBANY — The number of exonerations involving misconduct by police, prosecutors and other government officials is at an all-time high, according to a report released Wednesday by the National Registry of Exonerations.

The registry recorded 139 exonerations in the U.S. last year, a decline from the 171 reported in 2016. A record-high 84 exonerations—out of the 139—involved misconduct by police, prosecutors and other government officials, according to the report.

Last year also saw a record high, 37, for the number of cases involving mistaken eyewitness identification, as well as a record-setting 29 exonerations related to false confessions. Eighty-seven exonerations involved perjury or false accusations, the report said.

“The causes of wrongful convictions have always been there—mistaken eyewitnesses, false confessions, perjury and false accusations, faulty forensic evidence, and official misconduct,” said Michigan State University law professor Barbara O'Brien, the editor of the registry. “Fifty or a hundred years ago, an innocent defendant in prison had no one to turn to. The main reason we're seeing more exonerations now is that they can seek help from innocence organizations and prosecutors' offices who are committed to fixing wrongful convictions and are increasingly working together.”

Most of the exonerations recorded last year were the result of the efforts of “professional exonerators,” such as conviction integrity units in local district attorneys' offices and innocence organizations, such as the Innocence Project, Centurion Ministries and wrongful-conviction clinics at law schools. Nongovernmental innocence projects, according to the report, played a role in 54 exonerations in 2017.

Texas was identified in the report as the state with the most exonerations last year, coming in with 23. Illinois followed with 21 exonerations, with just under half of the exonerations coming from Cook County. Michigan, New York and California recorded 13, 13 and 9 exonerations, respectively, the report said.

In New York, the majority of the exonerations came from Cayuga County and involved four black men and one Hispanic man who were inmates at the Auburn Correctional Facility, according to the report. All of the men exonerated were charged with weapons possession after they were found with shanks or other weapons. Of the 13 exonerations in New York last year, only one was white.

Cory Epps, who was convicted in 1998 of the shooting death of a 23-year-old woman in Buffalo and facing a 25-year-to-life sentence, was exonerated in 2017. Epps, who was represented by attorneys at the New York City-based Exoneration Initiative, was convicted following a mistaken witness identification. Official misconduct was also listed as a contributing factor to Epps' incarceration. Lawyers for Epps did not immediately respond to a request for comment.

Ninety-eight of the exonerations recorded last year involved violent felonies, including 51 homicides, 16 child sex abuse convictions and 13 adult sexual assaults. Four individuals who were exonerated for homicides had been sentenced to death.

In addition to the 139 exonerations listed by the registry, the report also discussed an additional 96 other defendants in Chicago and Baltimore who were exonerated in group exonerations that occurred after it was discovered that police officers were “systematically framing” people for drug crimes. At least 30 additional defendants have been exonerated in 2018, with more expected, according to the report.

The drop in the number of exonerations last year was due to a decrease in cases from one county in Texas, the report said. A backlog of drug possession cases from Harris County has been “largely cleared” after three years, which “makes the long-term upward trend in exonerations clearer,” the report said.